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PYQ Paper

UPSC Prelims 2023 CSAT Paper II with Answer Key & Solutions | LearnPro

1. Overall Difficulty Level

The UPSC CSAT 2023 question paper, based on the provided extract, can be assessed as moderately difficult to challenging. A significant portion of the questions required careful analytical thinking and precise interpretation, particularly in the Reading Comprehension section. The Quantitative Aptitude and Logical Reasoning sections also presented problems that went beyond basic application of formulas, demanding systematic analysis and a strong grasp of number properties.

  • Easy: 10 questions
  • Medium: 26 questions
  • Difficult: 2 questions

The paper was challenging due to the nuanced nature of comprehension options, which often required distinguishing between closely related ideas or avoiding over-inference. In quantitative aptitude, questions like Q40 (ratio of number to sum of digits) and Q35 (scoring runs) demanded methodical case analysis, contributing to the higher difficulty. The presence of multi-statement questions across both sections further increased the cognitive load and potential for errors.

2. Nature of Questions

The question paper exhibited a diverse range of question design patterns, testing various cognitive abilities. The primary patterns observed were:

  • Passage-based Comprehension: 15 questions (Q1-5, Q11-13, Q21-23, Q31-33). These included:
    • Assumptions: 3 questions (Q1, Q3, Q5), all multi-statement with Roman numeral options, requiring careful evaluation of implied information.
    • Best reflects/Crux/Implication/Inference: 12 questions (Q2, Q4, Q11, Q12, Q13, Q21, Q22, Q23, Q31, Q32, Q33), typically single-choice, demanding identification of the core message or logical extension of the passage.
  • Quantitative Aptitude & Logical Reasoning: 23 questions (Q6-10, Q14-20, Q24-30, Q34-40). These included:
    • Number Theory: 11 questions (e.g., Q15 on divisibility, Q17 on remainders, Q26 on digit puzzles, Q40 on number properties).
    • Logical Reasoning (Puzzles/Arrangements): 4 questions (e.g., Q8 on age relations, Q9 on blood relations, Q29 on digit arrangement).
    • Permutations & Combinations: 3 questions (Q20 on triangles, Q35 on scoring runs, Q36 on letters/envelopes).
    • Pigeonhole Principle: 2 questions (Q6 on balls, Q34 on shoes), requiring worst-case scenario analysis.
    • Coding-Decoding: 1 question (Q7).
    • Time & Work: 1 question (Q30).
    • Number Properties (Even/Odd): 1 question (Q24).

The paper primarily tested conceptual understanding and analytical thinking. For comprehension, the ability to discern subtle differences in meaning and avoid external information was crucial. For quantitative sections, application-based reasoning and systematic problem-solving were frequently required, rather than mere factual recall of formulas.

3. Time Consumption

The paper was notably time-intensive, demanding strong time management skills from aspirants. Several factors contributed to this:

  • Lengthy Reading Comprehension Passages and Options: Many passages, though not excessively long, required careful reading and re-reading to grasp nuances. The options for comprehension questions were often subtly worded, necessitating thorough evaluation to identify the best fit, consuming valuable time.
  • Multi-Statement Questions: Questions with multiple Roman numeral statements (e.g., Q1, Q3, Q5, Q24, Q25, Q36) required individual assessment of each statement, effectively multiplying the effort for a single question.
  • Quantitative Aptitude Problems Requiring Case Analysis: Several quantitative questions (e.g., Q35 on scoring runs, Q40 on number properties, Q26 on digit puzzles) could not be solved by direct formula application. They demanded systematic listing of possibilities, trial-and-error, or logical deduction, which are inherently time-consuming.
  • Pigeonhole Principle Questions: Problems like Q6 and Q34, while conceptually straightforward, required careful visualization of worst-case scenarios, which can be mentally taxing and time-consuming under exam pressure.

Aspirants who lacked efficient reading strategies or systematic problem-solving approaches for quantitative questions would likely have struggled to complete the paper within the stipulated time.

4. Subject-Wise Distribution

The provided extract covers a balanced distribution across Reading Comprehension and Quantitative Aptitude/Logical Reasoning. The breakdown is as follows:

  • Reading Comprehension: 15 questions
  • Number System/Theory: 11 questions (Q15, Q17, Q18, Q19, Q25, Q26, Q27, Q37, Q38, Q39, Q40)
  • Logical Reasoning (Puzzles/Arrangements): 4 questions (Q8, Q9, Q10, Q29)
  • Permutations & Combinations: 3 questions (Q20, Q35, Q36)
  • Pigeonhole Principle: 2 questions (Q6, Q34)
  • Time & Work: 1 question (Q30)
  • Coding-Decoding: 1 question (Q7)
  • Number Properties (Even/Odd): 1 question (Q24)

For the top 3 subjects:

  • Reading Comprehension: Key themes included waste management (Q1, Q2), organic farming practices (Q3, Q4), food and nutrition security (Q5, Q23), air pollution policy (Q11), corporate governance (Q12), ecological roles of species (Q13), climate change uncertainty (Q21, Q33), public health and lifestyle choices (Q22, Q32), and water resource management (Q31).
  • Number System/Theory: Sub-topics covered divisibility rules (Q15, Q27, Q37), finding remainders (Q17), unit digits (Q38), sum of digits (Q18, Q19), properties of prime and composite numbers (Q25), and digit-based puzzles (Q26, Q39, Q40).
  • Logical Reasoning / Permutations & Combinations: This category included questions on age relations (Q8), blood relations (Q9), identifying patterns in number groups (Q10), forming numbers with specific digit constraints (Q29), counting triangles from given points (Q20), ways to score runs (Q35), and probability/derangements-like scenarios (Q36).

5. Static vs Current Affairs Orientation

The CSAT paper, by its very nature, primarily tests aptitude and analytical skills, which are static in their core principles. However, the themes chosen for the Reading Comprehension passages often reflect contemporary socio-economic and environmental issues, giving them a current affairs orientation in terms of context, even if the questions themselves demand analytical skills rather than factual recall.

Approximately 20-25% of the questions (the comprehension passages) had a thematic link to current affairs, while the remaining 75-80% (Quantitative Aptitude and Logical Reasoning) were purely static in their content. For instance, passages on municipal waste management (Q1, Q2), organic farming (Q3, Q4), food and nutrition security (Q5, Q23), air pollution policies (Q11), corporate governance (Q12), climate change adaptation (Q21, Q33), water stress (Q31), and health and nutrition (Q32) are all topics frequently discussed in public discourse and policy debates. While understanding these topics might provide a contextual advantage, the answers were strictly derivable from the provided text, emphasizing reading comprehension skills over external knowledge. The quantitative and logical reasoning questions were entirely based on static mathematical and logical principles.

6. Conceptual Depth

The conceptual depth required for the CSAT 2023 paper, as evidenced by this extract, appears to be higher than in some previous years. It moved beyond superficial understanding and rote application of formulas, demanding a multi-layered analysis and application-based reasoning.

  • Multi-layered Analysis: In comprehension, questions often required distinguishing between direct statements, implied meanings, and underlying assumptions. For example, Q22 (rational assumption from passage on health/environment) and Q4 (logical message on organic farming) required careful thought to avoid misinterpretation or selecting extreme options.
  • Elimination Techniques: The options provided for comprehension questions were frequently close, making elimination a critical strategy. Aspirants needed to identify subtle flaws or overstatements in incorrect options to arrive at the most appropriate answer.
  • Application-based Reasoning: In quantitative aptitude, questions like Q35 (scoring runs) and Q40 (ratio of number to sum of digits) were not solvable by a single formula. They required a systematic approach, breaking down the problem into cases, or applying number properties in a logical sequence. Similarly, pigeonhole principle questions (Q6, Q34) tested the ability to construct worst-case scenarios, which is an application of logical reasoning rather than a direct formula.

While foundational concepts from standard sources (like basic mathematics for quantitative aptitude) are necessary, the paper tested the ability to apply these concepts in complex, multi-step problems. Deeper reading and extensive practice with varied problem types, focusing on analytical thinking, would have been more beneficial than merely memorizing facts or formulas.

7. Key Takeaways for Aspirants

  • Master Reading Comprehension Nuances: Practice identifying the author’s main idea, assumptions, implications, and inferences. Pay close attention to keywords and avoid bringing in outside information. Focus on distinguishing between direct statements, logical extensions, and extreme or unsupported claims.
  • Strengthen Number System and Quantitative Aptitude: Dedicate significant time to number theory concepts, including divisibility rules, remainders, unit digits, and properties of numbers. Practice a wide variety of digit-based puzzles and problems requiring systematic case analysis.
  • Develop Systematic Problem-Solving for P&C and Logical Reasoning: For permutations, combinations, and logical puzzles (age, blood relations, arrangements), adopt a structured approach. Break down complex problems into smaller, manageable steps and practice careful enumeration or deduction.
  • Practice Worst-Case Scenario Analysis: Questions based on the Pigeonhole Principle (e.g., drawing balls/shoes) are common. Understand the logic behind worst-case scenarios to accurately determine minimum or maximum possibilities.
  • Prioritize Time Management: The paper is time-intensive. Practice solving questions under timed conditions to improve speed and accuracy. Develop strategies for quickly identifying solvable questions and managing time for more complex ones.
  • Focus on Conceptual Understanding over Rote Learning: The paper tests the application of concepts rather than mere recall. A deep understanding of underlying principles in mathematics and logical reasoning is crucial for tackling non-standard problems.
  • Regular Practice with Diverse Question Types: Consistent practice across all sections, including multi-statement questions and problems requiring multi-step solutions, is essential to build confidence and proficiency.

Complete Question Paper

80 questions
Question 1Permanent link
Based on the above passage, the following assumptions have been made: 1. Collection, processing and segregation of municipal waste should be with government agencies. 2. Resource recovery and recycling require technological inputs that can be best handled by private sector enterprises. Which of the assumptions given above is/are correct?
  1. A. 1 only
  2. B. 2 only
  3. C. Both 1 and 2
  4. D. Neither 1 nor 2
Show answer and explanation

Answer: D

Explanation

The passage describes the current state of waste management in India, highlighting issues like rare source segregation and budget allocation for collection and transportation. It discusses the ideal placement of waste-to-energy in the process and mentions biomethanation as a solution. However, the passage does not make any assertions or assumptions about whether government agencies or private sector enterprises should be responsible for collection, processing, segregation, or technological inputs. It focuses on the 'what' and 'how' of waste management, not the 'who'. Therefore, neither statement 1 nor statement 2 can be assumed from the text provided. This question tests the ability to strictly adhere to the information given in the passage.

Question 2Permanent link
Which one of the following statements best reflects the crux of the passage?
  1. A. Generation of energy from municipal solid waste is inexpensive.
  2. B. Biomethanation is the most ideal way of generating energy from municipal solid waste.
  3. C. Segregation of municipal solid waste is the first step in ensuring the success of waste-to-energy plants.
  4. D. The biodegradable component of India's municipal solid waste is not adequate to provide energy from waste efficiently/effectively.
Show answer and explanation

Answer: C

Explanation

The passage begins by highlighting the rarity of municipal waste segregation at source in India. It then explicitly states that for waste-to-energy, it 'Ideally it fits in the chain after segregation (between wet waste and rest), collection, recycling, and before getting to the landfill.' This clearly positions segregation as a foundational and initial step for the effective functioning of waste-to-energy processes. Options A and D are not supported by the passage, as it doesn't discuss cost or inadequacy. Option B is an overstatement; biomethanation is called a 'major solution,' not the 'most ideal way.' The central theme revolves around the critical importance of segregation.

Question 3Permanent link
Based on the above passage, the following assumptions have been made: 1. Organic farming is inherently unsafe for both farmers and consumers. 2. Farmers and consumers need to be educated about eco-friendly food. Which of the assumptions given above is/are correct?
  1. A. 1 only
  2. B. 2 only
  3. C. Both 1 and 2
  4. D. Neither 1 nor 2
Show answer and explanation

Answer: B

Explanation

Statement 1 is incorrect because the passage attributes potential harm in organic farming to factors like lack of regulation, difficulty in sourcing proper organic fertilizers, and insufficient research on application doses, rather than organic farming being 'inherently' unsafe. The word 'inherently' makes the statement too strong. Statement 2 is a valid assumption. The passage explicitly mentions that farmers and consumers are 'confused about what products are best for them' and that issues like dosage are 'not well-researched or regulated.' This directly implies a need for better education and guidance regarding safe and eco-friendly organic practices for both farmers and consumers.

Question 4Permanent link
Which one of the following statements best reflects the most logical, rational and practical message conveyed by the author of the passage?
  1. A. In India, organic farming should not be promoted as a substitute for conventional farming.
  2. B. There are no safe organic alternatives to chemical fertilizers.
  3. C. In India, farmers need to be guided and helped to make their organic farming sustainable.
  4. D. The aim of organic farming should not be to generate huge profits as there is still no global market for its products.
Show answer and explanation

Answer: C

Explanation

The passage details the challenges faced by India's organic farming sector, including its nascent stage, lack of regulation, confusion among stakeholders, and potential misuse of organic inputs due to lack of knowledge. The author's examples of farmyard manure and Datura spray highlight the need for proper guidance and research. This strongly suggests that for organic farming to be truly beneficial and sustainable in India, farmers require support and education. Options A and B are extreme and not supported by the passage, which points to issues with current practices, not a fundamental flaw in organic farming itself. Option D is outside the scope of the passage, which focuses on safety and regulation, not market profitability.

Question 5Permanent link
Based on the above passage, the following assumptions have been made: 1. To implement the Sustainable Development Goals and to achieve zero-hunger goal, monoculture agriculture practices are inevitable even if they do not address malnutrition. 2. Dependence on a few crops has negative consequences for human health and the ecosystem. 3. Government policies regarding food planning need to incorporate nutritional security. 4. For the present monoculture agriculture practices, farmers receive subsidies in various ways and government offers remunerative prices for grains and therefore they do not tend to consider crop diversity. Which of the above assumptions are valid?
  1. A. 1, 2 and 4 only
  2. B. 2 and 3 only
  3. C. 3 and 4 only
  4. D. 1, 2, 3 and 4
Show answer and explanation

Answer: B

Explanation

Statement 1 is incorrect; the passage criticizes monoculture, stating it 'can perpetuate the food and nutrition security problem,' implying it is detrimental, not inevitable or desirable for achieving goals like zero-hunger. Statement 2 is correct; the passage explicitly links the focus on staples to 'lower production and consumption of indigenous traditional crops... impacting food and nutrition security' and mentions monoculture degrading land/water quality, showing negative consequences. Statement 3 is correct; the passage highlights that increased food production hasn't addressed malnutrition and that current practices impact nutrition security, strongly implying a need for government policies to prioritize nutritional aspects. Statement 4 is outside the scope of the passage; it does not discuss subsidies or remunerative prices as reasons for monoculture.

Question 6Permanent link
A box contains 14 black balls, 20 blue balls, 26 green balls, 28 yellow balls, 38 red balls and 54 white balls. Consider the following statements: 1. The smallest number n such that any n balls drawn from the box randomly must contain one full group of at least one colour is 175. 2. The smallest number m such that any m balls drawn from the box randomly must contain at least one ball of each colour is 167. Which of the above statements is/are correct?
  1. A. 1 only
  2. B. 2 only
  3. C. Both 1 and 2
  4. D. Neither 1 nor 2
Show answer and explanation

Answer: C

Explanation

For statement 1 (n): To guarantee one full group, we consider the worst-case scenario where we pick one less than the full count for each color. This sum is (14-1) + (20-1) + (26-1) + (28-1) + (38-1) + (54-1) = 13 + 19 + 25 + 27 + 37 + 53 = 174 balls. The next ball (175th) *must* complete a full group of some color. So, n = 175. Statement 1 is correct. For statement 2 (m): To guarantee at least one ball of each color, we consider the worst-case scenario where we pick all balls of all but one color. To maximize this, we pick all balls of the five largest groups: 20 (blue) + 26 (green) + 28 (yellow) + 38 (red) + 54 (white) = 166 balls. The next ball (167th) *must* be a black ball, ensuring at least one of each color. So, m = 167. Statement 2 is correct.

Question 7Permanent link
If 'ZERO' is written as 'CHUR', then how is 'PLAYER' written?
  1. A. SOCACT
  2. B. SODBGT
  3. C. SODBHT
  4. D. SODBHU
Show answer and explanation

Answer: D

Explanation

To decode the pattern, let's compare the letters of 'ZERO' and 'CHUR':
Z (26th letter) + 3 = C (3rd letter, wrapping around A, B, C)
E (5th letter) + 3 = H (8th letter)
R (18th letter) + 3 = U (21st letter)
O (15th letter) + 3 = R (18th letter)
The pattern is to shift each letter forward by 3 positions in the alphabet. Applying this rule to 'PLAYER':
P (16th) + 3 = S (19th)
L (12th) + 3 = O (15th)
A (1st) + 3 = D (4th)
Y (25th) + 3 = B (2nd, wrapping around Z, A, B)
E (5th) + 3 = H (8th)
R (18th) + 3 = U (21st)
Thus, 'PLAYER' is written as 'SODBHU'.

Question 8Permanent link
Consider the following statements: 1. A is older than B. 2. C and D are of the same age. 3. E is the youngest. 4. F is younger than D. 5. F is older than A. How many statements given above are required to determine the oldest person/persons?
  1. A. Only two
  2. B. Only three
  3. C. Only four
  4. D. All five
Show answer and explanation

Answer: D

Explanation

To determine the oldest person, we need to establish the complete relative age order of all individuals. Let's combine the statements:
1. A > B
2. C = D
3. E is the youngest (E F
5. F > A

Combining (1) and (5): F > A > B.
Combining this with (2) and (4): C = D > F > A > B.
Finally, incorporating (3): C = D > F > A > B > E.
This complete sequence shows that C and D are the oldest. Each statement provides a unique and essential link in establishing this order. Removing any one statement would break a link and prevent the definitive identification of the oldest person(s). Therefore, all five statements are required.

Question 9Permanent link
Consider the following including the Question and the Statements: There are 5 members A, B, C, D, E in a family. Question: What is the relation of E to B ? Statement-1: A and B are a married couple. Statement-2: D is the father of C. Statement-3: E is D's son. Statement-4: A and C are sisters. Which one of the following is correct in respect of the above Questions and Statements?
  1. A. Statement-1, Statement-2 and Statement-3 are sufficient to answer the Question.
  2. B. Statement-1, Statement-3 and Statement-4 are sufficient to answer the Question.
  3. C. All four statement together are sufficient to answer the Question.
  4. D. All four statements are not sufficient to answer the Question.
Show answer and explanation

Answer: C

Explanation

Let's deduce the relationships using all statements:
1. A and B are a married couple.
2. D is the father of C.
3. E is D's son.
4. A and C are sisters.

From (2) and (3), D is the father of both C and E, making C and E siblings. From (4), A and C are sisters. This means A is also D's daughter. Since A is D's daughter and E is D's son, A and E are siblings. From (1), A and B are a married couple. If A is female (sister of C), then B must be her husband. Since E is A's brother, E is B's brother-in-law. All four statements are necessary to establish these connections and determine the precise relationship between E and B.

Question 10Permanent link
Choose the group which is different from the others: (a) 17, 37, 47, 97 (b) 31, 41, 53, 67 (c) 71, 73, 79, 83 (d) 83, 89, 91, 97
  1. A. 17, 37, 47, 97
  2. B. 31, 41, 53, 67
  3. C. 71, 73, 79, 83
  4. D. 83, 89, 91, 97
Show answer and explanation

Answer: D

Explanation

To identify the different group, we examine the properties of the numbers in each option:
(a) 17, 37, 47, 97 are all prime numbers.
(b) 31, 41, 53, 67 are all prime numbers.
(c) 71, 73, 79, 83 are all prime numbers.
(d) 83, 89, 91, 97. In this group, 83, 89, and 97 are prime numbers. However, 91 is a composite number, as it can be factored into 7 × 13. Since group (d) contains a composite number while the others contain only prime numbers, it is the different group.

Question 11Permanent link
Which one of the following statements best reflects the most logical and rational implication conveyed by the passage?
  1. A. Arbitrary curbs on vehicles to reduce pollution are difficult to implement.
  2. B. Knee-jerk reactions cannot but an evidence-based approach will be more effective.
  3. C. A heavy penalty should be enforced on those driving without periodic pollution tests.
  4. D. In the absence of laws to deal with the problem of pollution, the administration tends to make arbitrary decisions.
Show answer and explanation

Answer: B

Explanation

The passage critiques 'drastic actions' and 'arbitrary bans' as ineffective, noting that 'Even then the air is not clean.' It provides examples of such measures being disproportionate or lacking scientific basis. The concluding sentence explicitly states, 'What is needed is the scientific and reliable information about the source of pollutants on a continuing basis and the technologies that will work to reduce pollution from them.' This clearly implies that impulsive, non-scientific measures (knee-jerk reactions) are ineffective, and a data-driven, evidence-based approach is essential for effective pollution control. Options A, C, and D are not the central implication; the passage focuses on the *quality* and *basis* of policy decisions, not their implementation difficulty, specific penalties, or absence of laws.

Question 12Permanent link
Which of the following statements best reflects the logical inference from the passage given above?
  1. A. It is an important agenda of the countries around the world to ensure access to good external financing.
  2. B. Good corporate governance improves the credibility of the firms.
  3. C. International capital markets ensure that the firms maintain good corporate governance.
  4. D. Good corporate governance paves the way for robust supply chains.
Show answer and explanation

Answer: B

Explanation

The passage states that 'Good corporate governance structures encourage companies to provide accountability and control' and that 'Investors look to place their funds where the standards of disclosure, of timely and accurate financial reporting, and of equal treatment to all stakeholders are met.' This directly implies that good corporate governance builds trust and confidence among investors by ensuring transparency and fair treatment. This trust and confidence are synonymous with improving the credibility of the firms, which in turn enhances their access to external financing. Options A and C misrepresent the cause-effect relationship or are secondary points. Option D is outside the scope of the passage.

Question 13Permanent link
Which one of the following statements best reflects the most logical and rational inference that can be drawn from the passage?
  1. A. The home range of elephants needs to be a vast area of rich biodiversity.
  2. B. Elephants are the keystone species and they benefit the biodiversity.
  3. C. Rich biodiversity cannot be maintained in the forests without the presence of elephants.
  4. D. Elephants are capable of regenerating forests with species as per their requirement.
Show answer and explanation

Answer: B

Explanation

The passage details numerous ways elephants significantly impact and shape their ecosystem: creating clearings, preventing overgrowth, aiding seed dispersal, enriching soil with dung, and providing water sources during droughts. These actions demonstrate that elephants play a critical and disproportionately large role in maintaining the structure and health of their environment, which is the definition of a keystone species. Their activities directly benefit the overall biodiversity of the ecosystem. Option A is not directly inferred. Option C is an extreme statement ('cannot be maintained') not fully supported. Option D misrepresents their ecological role as being 'as per their requirement' rather than a natural, often involuntary, process.

Question 14Permanent link
If 7  9  10 = 8, 9  11  30 = 5, 11  17  21 = 13, what is the value of 23  4  15 ?
  1. A. 6
  2. B. 8
  3. C. 13
  4. D. 15
Show answer and explanation

Answer: A

Explanation

Let's analyze the given operations to find the pattern:
1. 7  9  10: Sum = 7 + 9 + 10 = 26. The result is 8, which is the sum of the digits of 26 (2+6=8).
2. 9  11  30: Sum = 9 + 11 + 30 = 50. The result is 5, which is the sum of the digits of 50 (5+0=5).
3. 11  17  21: Sum = 11 + 17 + 21 = 49. The result is 13, which is the sum of the digits of 49 (4+9=13).

The pattern is to sum all the numbers involved in the operation, and then sum the digits of that total sum. Applying this to the final expression:
23  4  15: Sum = 23 + 4 + 15 = 42.
Sum of the digits of 42 = 4 + 2 = 6.
Therefore, the value is 6.

Question 15Permanent link
Let x be a positive integer such that 7x + 96 is divisible by x. How many values of x are possible?
  1. A. 10
  2. B. 11
  3. C. 12
  4. D. Infinitely many
Show answer and explanation

Answer: C

Explanation

For (7x + 96) to be divisible by x, the expression (7x + 96) / x must result in an integer. We can rewrite this expression as:
(7x / x) + (96 / x) = 7 + (96 / x).
Since 7 is an integer, for the entire expression to be an integer, 96/x must also be an integer. This implies that x must be a divisor (or factor) of 96.
To find the number of positive factors of 96, we first find its prime factorization:
96 = 2 × 48 = 2 × 2 × 24 = 2 × 2 × 2 × 12 = 2 × 2 × 2 × 2 × 6 = 2 × 2 × 2 × 2 × 2 × 3 = 2^5 × 3^1.
The number of factors is calculated by adding 1 to each exponent in the prime factorization and multiplying the results: (5+1) × (1+1) = 6 × 2 = 12.
Thus, there are 12 possible positive integer values for x (1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 96).

Question 16Permanent link
If p, q, r and s are distinct single digit positive numbers, then what is the greatest value of (p + q) (r + s) ?
  1. A. 230
  2. B. 225
  3. C. 224
  4. D. 221
Show answer and explanation

Answer: B

Explanation

To maximize the product of two sums, (p+q)(r+s), where p, q, r, s are distinct single-digit positive numbers, we should select the largest available distinct single-digit positive numbers. These are 1, 2, 3, 4, 5, 6, 7, 8, 9. The four largest distinct single-digit positive numbers are 9, 8, 7, and 6.
Next, to maximize the product of two factors, the factors should be as close to each other in value as possible. We need to group these four numbers into two pairs such that their sums are nearly equal.
Possible groupings and sums:
1. (9+8) = 17, (7+6) = 13. Product = 17 × 13 = 221.
2. (9+7) = 16, (8+6) = 14. Product = 16 × 14 = 224.
3. (9+6) = 15, (8+7) = 15. Product = 15 × 15 = 225.
Comparing these products, the greatest value is 225.

Question 17Permanent link
A number N is formed by writing 9 for 99 times. What is the remainder if N is divided by 13 ?
  1. A. 11
  2. B. 9
  3. C. 7
  4. D. 1
Show answer and explanation

Answer: A

Explanation

The number N consists of 99 nines. This can be written as N = 9 * (10^99 - 1) / 9 = 10^99 - 1. We need to find (10^99 - 1) mod 13.
First, let's find the cycle of powers of 10 modulo 13:
10^1 ≡ 10 (mod 13)
10^2 ≡ 100 ≡ 9 (mod 13)
10^3 ≡ 10 * 9 = 90 ≡ 12 (mod 13) or -1 (mod 13)
10^4 ≡ 10 * 12 = 120 ≡ 3 (mod 13)
10^5 ≡ 10 * 3 = 30 ≡ 4 (mod 13)
10^6 ≡ 10 * 4 = 40 ≡ 1 (mod 13)
The cycle length (order) of 10 modulo 13 is 6.
Now, divide the exponent 99 by the cycle length 6: 99 = 6 × 16 + 3.
So, 10^99 ≡ (10^6)^16 × 10^3 ≡ 1^16 × 10^3 ≡ 10^3 (mod 13).
From our cycle, 10^3 ≡ 12 (mod 13).
Therefore, N ≡ (10^99 - 1) ≡ (12 - 1) ≡ 11 (mod 13).
The remainder is 11.

Question 18Permanent link
Each digit of a 9-digit number is 1. It is multiplied by itself. What is the sum of the digits of the resulting number?
  1. A. 64
  2. B. 80
  3. C. 81
  4. D. 100
Show answer and explanation

Answer: C

Explanation

Let the 9-digit number be R9 (a repunit of 9 ones), i.e., 111,111,111. We need to find the sum of the digits of R9 × R9.
Consider smaller repunits squared:
1^2 = 1 (Sum of digits = 1 = 1^2)
11^2 = 121 (Sum of digits = 1+2+1 = 4 = 2^2)
111^2 = 12321 (Sum of digits = 1+2+3+2+1 = 9 = 3^2)
1111^2 = 1234321 (Sum of digits = 1+2+3+4+3+2+1 = 16 = 4^2)
This pattern shows that for a number consisting of 'n' ones, its square results in a number whose digits sum to n^2. For a 9-digit number of all ones (n=9), the sum of the digits of its square will be 9^2 = 81.
Alternatively, a number consisting of 'n' ones is divisible by 9 if n is a multiple of 9. Here, n=9, so 111,111,111 is divisible by 9. Its square will also be divisible by 9. The sum of digits of any number divisible by 9 must also be divisible by 9. Among the options, only 81 is divisible by 9.

Question 19Permanent link
What is the sum of all digits which appear in all the integers from 10 to 100 ?
  1. A. 855
  2. B. 856
  3. C. 910
  4. D. 911
Show answer and explanation

Answer: B

Explanation

We need to calculate the sum of all digits from 10 to 100.
1. For numbers from 10 to 99:
- Units digits: The digits 0, 1, 2, ..., 9 each appear 9 times (e.g., 10, 20, ..., 90 for 0; 11, 21, ..., 91 for 1). The sum of digits from 0 to 9 is (9 * 10) / 2 = 45. So, the sum of all units digits is 9 × 45 = 405.
- Tens digits: The digits 1, 2, ..., 9 each appear 10 times (e.g., 10-19 for 1; 20-29 for 2). The sum of digits from 1 to 9 is 45. So, the sum of all tens digits is 10 × 45 = 450.
- Total sum for numbers 10-99 = 405 (units) + 450 (tens) = 855.
2. For the number 100:
- The digits are 1, 0, 0. Their sum is 1 + 0 + 0 = 1.

Adding these two parts: Total sum of all digits from 10 to 100 = 855 + 1 = 856.

Question 20Permanent link
ABCD is a square. One point on each of AB and CD; and two distinct points on each of BC and DA are chosen. How many distinct triangles can be drawn using any three points as vertices out of these six points?
  1. A. 16
  2. B. 18
  3. C. 20
  4. D. 24
Show answer and explanation

Answer: C

Explanation

Let's list the chosen points:
- One point on side AB (let's call it P1)
- One point on side CD (P2)
- Two distinct points on side BC (P3, P4)
- Two distinct points on side DA (P5, P6)
In total, there are 1 + 1 + 2 + 2 = 6 distinct points.
To form a triangle, we need to choose any 3 points from these 6 points. The total number of ways to choose 3 points from 6 is given by the combination formula 6C3.
6C3 = 6! / (3! * (6-3)!) = (6 × 5 × 4) / (3 × 2 × 1) = 20.
For these points to form a triangle, no three chosen points should be collinear. In this setup, points P3 and P4 are collinear (on BC), and P5 and P6 are collinear (on DA). However, no three points from the entire set of 6 can be collinear. For example, P1 (on AB), P3 (on BC), and P5 (on DA) cannot be collinear. Similarly, P1, P3, P4 cannot be collinear as P1 is on AB and P3, P4 are on BC. Since no three points are collinear, every combination of 3 points will form a distinct triangle. Thus, the total number of distinct triangles is 20.

Question 21Permanent link
Which one of the following statements best reflects the crucial message conveyed by the author of the passage?
  1. A. Businesses that cause emissions may need to close down or pay for pollution in future.
  2. B. The only solution is technological development related to the issues of climate change.
  3. C. Waiting to deal with carbon emissions until technology improves is not a wise strategy.
  4. D. Since future technological change is uncertain, new industries should be based on renewable energy sources.
Show answer and explanation

Answer: C

Explanation

The passage emphasizes the uncertainty of future technological advancements making emission reduction cheaper. It warns that relying on such uncertain future technology could lead to a 'terrible choice' between costly immediate action or severe consequences of unchecked warming. The analogy of businesses failing due to not hedging against uncertain outcomes reinforces the idea that delaying action on climate change, hoping for future technological fixes, is a reckless and unwise strategy. Therefore, the crucial message is to act now rather than wait. Options A, B, and D are either too specific, too extreme, or not the central warning of the passage.

Question 22Permanent link
Which one of the following statements best implies the most rational assumption that can be made from the passage?
  1. A. We are likely to spend more money on cure than prevention.
  2. B. It is the job of the government to solve our environmental and public health problems.
  3. C. Health can be protected even if environmental problems go on unattended.
  4. D. Loss of traditional lifestyle and the influence of western values led to some unhealthy way of living.
Show answer and explanation

Answer: A

Explanation

The passage highlights a 'collective lethargy towards making choices' that could improve health, despite individual choices having a significant impact. This resistance to adopting 'substantial changes in lifestyle' for health, even when such changes are crucial, implies a societal tendency to avoid proactive, preventive measures. This often results in a reactive approach, where problems are addressed after they manifest, leading to greater expenditure on 'cure' rather than 'prevention.' The author's tone suggests this is a 'peculiar' and 'lethargic' response, making the inference about prioritizing cure over prevention a rational assumption about societal behavior. Options B and D are outside the scope of the passage. Option C is problematic because the passage explicitly states 'Environmental problems cause health problems,' implying a direct link that cannot be entirely ignored for health protection.

Question 23Permanent link
Which one of the following statements best reflects the crux of the passage?
  1. A. The scheme of Universal Basic Income should be implemented worldwide as a way of poverty alleviation.
  2. B. We must place food-based nutrition at the centre of our policy debate.
  3. C. Nutritional status of food should be improved by creating appropriate genetically modified crops.
  4. D. Using modern food processing technologies, we must fortify food items with required nutrient elements.
Show answer and explanation

Answer: B

Explanation

The passage comprehensively outlines various facets of the nutrition problem: unhealthy food choices, limited access to nutritious food, affordability issues, and ultimately, food systems failing to meet nutritional needs. It highlights the severe consequences, including increased non-communicable diseases, strain on healthcare, and hindered economic progress. The overarching message is that nutrition is a multifaceted and critical issue with profound societal and economic impacts. Therefore, the most logical conclusion is that food-based nutrition must be a central focus in policy discussions to address these interconnected problems effectively. Options A, C, and D propose specific solutions not explicitly discussed as the main point of the passage.

Question 24Permanent link
Three of the five positive integers p, q, r, s, t are even and two of them are odd (not necessarily in order). Consider the following: 1. p + q + r – s - t is definitely even. 2. 2p + q + 2r - 2s + t is definitely odd. Which of the above statements is/are correct?
  1. A. 1 Only
  2. B. 2 Only
  3. C. Both 1 and 2
  4. D. Neither 1 nor 2
Show answer and explanation

Answer: A

Explanation

Let E represent an even number and O represent an odd number. Among p, q, r, s, t, there are 3 Even and 2 Odd numbers.

Statement 1: p + q + r – s - t
The sum of all five numbers (p+q+r+s+t) will have the parity of (3 Even numbers + 2 Odd numbers) = E + E = Even.
We can rewrite the expression as (p+q+r+s+t) - 2s - 2t. Since 2s and 2t are always even, subtracting them from an even sum (p+q+r+s+t) will result in an even number. Thus, p + q + r – s - t is definitely even. Statement 1 is correct.

Statement 2: 2p + q + 2r - 2s + t
Any number multiplied by 2 is even. So, 2p, 2r, and 2s are all even. The expression simplifies to (Even) + q + (Even) - (Even) + t, which has the same parity as q + t.
Since there are 2 odd and 3 even numbers among the five, q and t could be:
- Both Odd (O+O = Even)
- One Odd and one Even (O+E = Odd)
Since q+t can be either even or odd depending on the specific assignment of p,q,r,s,t, the expression is NOT definitely odd. Statement 2 is incorrect.
Therefore, only statement 1 is correct.

Question 25Permanent link
Consider the following in respect of prime number p and composite number c. 1. 𝑝+𝑐 / 𝑝−𝑐 can be even. 2. 2p+c can be odd. 3. pc can be odd. Which of the statements given above are correct?
  1. A. 1 and 2 only
  2. B. 2 and 3 only
  3. C. 1 and 3 only
  4. D. 1, 2 and 3
Show answer and explanation

Answer: D

Explanation

Let's evaluate each statement:
1. (p+c)/(p-c) can be even.
Consider p = 11 (an odd prime) and c = 9 (an odd composite number).
p+c = 11+9 = 20 (even)
p-c = 11-9 = 2 (even)
(p+c)/(p-c) = 20/2 = 10, which is an even number. So, statement 1 is correct.
2. 2p+c can be odd.
Since p is an integer, 2p will always be an even number. For 2p+c to be odd, c must be an odd number (Even + Odd = Odd).
Consider p = 3 (an odd prime) and c = 9 (an odd composite number).
2p+c = 2(3) + 9 = 6 + 9 = 15, which is an odd number. So, statement 2 is correct.
3. pc can be odd.
For the product of two integers to be odd, both integers must be odd.
Consider p = 3 (an odd prime) and c = 9 (an odd composite number).
pc = 3 × 9 = 27, which is an odd number. So, statement 3 is correct.
Since all three statements can be true, the correct option is D.

Question 26Permanent link
A 3-digit number ABC, on multiplication with D gives 37DD where A, B, C and D are different non-zero digits. What is the value of A+B+C ?
  1. A. 18
  2. B. 16
  3. C. 15
  4. D. Cannot be determined due to insufficient data
Show answer and explanation

Answer: A

Explanation

Given the equation: ABC × D = 37DD.
We can express 37DD as 3700 + 11D. So, ABC = (3700 + 11D) / D = 3700/D + 11.
Since ABC is a 3-digit number (100 ≤ ABC ≤ 999) and A, B, C, D are different non-zero digits (1-9), we can test values for D:
- If D=1, ABC = 3700/1 + 11 = 3711 (Not a 3-digit number).
- If D=2, ABC = 3700/2 + 11 = 1850 + 11 = 1861 (Not a 3-digit number).
- If D=3, ABC = 3700/3 + 11 = 1233.33 + 11 (Not an integer).
- If D=4, ABC = 3700/4 + 11 = 925 + 11 = 936. Here, A=9, B=3, C=6. All digits (9, 3, 6, 4) are different and non-zero. This is a valid solution.
A+B+C = 9+3+6 = 18.
- If D=5, ABC = 3700/5 + 11 = 740 + 11 = 751. Here, A=7, B=5, C=1. But B=D=5, which violates the condition that digits must be different.
- Other values of D (6, 7, 8, 9) will not yield an integer for 3700/D or will result in ABC being less than 100 or having repeated digits with D.
Thus, the only valid solution is A=9, B=3, C=6, and D=4. The sum A+B+C = 18.

Question 27Permanent link
For any choices of values of X, Y and Z, the 6 digit number of the form XYZXYZ is divisible by:
  1. A. 7 and 11 only
  2. B. 11 and 13 only
  3. C. 7 and 13 only
  4. D. 7, 11 and 13
Show answer and explanation

Answer: D

Explanation

A 6-digit number of the form XYZXYZ can be expressed mathematically as:
XYZXYZ = XYZ × 1000 + XYZ
= XYZ × (1000 + 1)
= XYZ × 1001
Now, we need to find the prime factors of 1001.
1001 can be divided by 7: 1001 ÷ 7 = 143.
143 can be divided by 11: 143 ÷ 11 = 13.
13 is a prime number.
So, the prime factorization of 1001 is 7 × 11 × 13.
Therefore, any number of the form XYZXYZ is always divisible by 7, 11, and 13.

Question 28Permanent link
125 identical cubes are arranged in the form of cubical block. How many cubes are surrounded by other cubes from each side?
  1. A. 27
  2. B. 25
  3. C. 21
  4. D. 18
Show answer and explanation

Answer: A

Explanation

When 125 identical cubes are arranged to form a larger cubical block, the side length of this larger cube (n) can be found by taking the cube root of the total number of small cubes.
So, n = ∛125 = 5. This means the large cubical block is a 5x5x5 arrangement of small cubes.
Cubes that are 'surrounded by other cubes from each side' are the internal cubes, meaning they are not on any of the outer surfaces of the larger block. To find the number of such cubes, we effectively remove one layer of cubes from each side (top, bottom, front, back, left, right).
The formula for the number of internal cubes in an n x n x n block is (n-2)^3.
Substituting n=5: (5-2)^3 = 3^3 = 27.
These 27 cubes form a 3x3x3 inner cube, completely enclosed by the outer layers.

Question 29Permanent link
How many distinct 8-digit numbers can be formed by rearranging the digits of the number 11223344 such that odd digits occupy odd positions and even digits occupy even positions?
  1. A. 12
  2. B. 18
  3. C. 36
  4. D. 72
Show answer and explanation

Answer: C

Explanation

The 8-digit number has 8 positions. The odd positions are 1st, 3rd, 5th, 7th (4 positions). The even positions are 2nd, 4th, 6th, 8th (4 positions).

The given digits are 1, 1, 2, 2, 3, 3, 4, 4.
Odd digits: 1, 1, 3, 3 (4 digits)
Even digits: 2, 2, 4, 4 (4 digits)

First, arrange the odd digits (1, 1, 3, 3) in the 4 odd positions. The number of ways to arrange these digits with repetitions is given by 4! / (2! × 2!) = (4 × 3 × 2 × 1) / ((2 × 1) × (2 × 1)) = 24 / 4 = 6 ways.

Next, arrange the even digits (2, 2, 4, 4) in the 4 even positions. Similarly, the number of ways is 4! / (2! × 2!) = 24 / 4 = 6 ways.

To find the total number of distinct 8-digit numbers, we multiply the number of ways to arrange the odd digits by the number of ways to arrange the even digits:
Total ways = 6 × 6 = 36.
Therefore, 36 distinct 8-digit numbers can be formed.

Question 30Permanent link
A, B, C working independently can do a piece of work in 8, 16 and 12 days respectively. A alone works on Monday, B alone works on Tuesday, C alone works on Wednesday; A alone, again works on Thursday and so on. consider the following statements: 1. The work will be finished on Thursday. 2. The work will be finished in 10 days. Which of the above statements is/are correct?
  1. A. 1 Only
  2. B. 2 Only
  3. C. Both 1 and 2
  4. D. Neither 1 nor 2
Show answer and explanation

Answer: A

Explanation

Let the total work be the Least Common Multiple (LCM) of 8, 16, and 12, which is 48 units.
Individual efficiencies:
A's efficiency = 48 units / 8 days = 6 units/day
B's efficiency = 48 units / 16 days = 3 units/day
C's efficiency = 48 units / 12 days = 4 units/day

The work pattern is A on Monday, B on Tuesday, C on Wednesday, then A on Thursday, and so on.
Work done in one 3-day cycle (Mon, Tue, Wed) = A + B + C = 6 + 3 + 4 = 13 units.

Let's track the progress:
- After 3 days (Mon-Wed): 13 units done. Remaining = 48 - 13 = 35 units.
- After 6 days (Thu-Sat): 13 + 13 = 26 units done. Remaining = 48 - 26 = 22 units.
- After 9 days (Sun-Tue): 26 + 13 = 39 units done. Remaining = 48 - 39 = 9 units.

Now, 9 units are remaining after 9 days (Tuesday).
- Day 10 (Wednesday): C works. C does 4 units. Remaining = 9 - 4 = 5 units.
- Day 11 (Thursday): A works. A does 6 units/day. Since only 5 units are remaining, A will complete the work on Thursday.

So, the work is finished on Day 11, which is a Thursday.
Statement 1: The work will be finished on Thursday. (Correct)
Statement 2: The work will be finished in 10 days. (Incorrect, it takes 11 days)
Therefore, only statement 1 is correct.

Question 31Permanent link
Which one of the following statements best reflects the most rational, practical and immediate action required to ensure fair and equitable allocation of water to different stakeholders?
  1. A. A national, pragmatic, legal and policy framework for water allocation should be made.
  2. B. All river systems of the country should be linked and huge aquifers created.
  3. C. Water channels between regions of water surplus and regions of water deficit should be created.
  4. D. To mitigate water crisis, water demand of sectors such as agriculture and industry should be reduced.
Show answer and explanation

Answer: A

Explanation

The passage highlights the complexity of water allocation, emphasizing inter-state conflicts, water stress, and the need for a basin-based approach with objective criteria. It also notes the Union's role in regulating inter-state rivers. Option (A) proposes a 'national, pragmatic, legal and policy framework,' which directly addresses the need for a structured, objective, and balanced approach, aligning with the passage's emphasis on objective criteria and the Union's role. Options (B) and (C) suggest large-scale infrastructure projects not explicitly presented as the 'most rational, practical and immediate action' in the text. Option (D) focuses on demand reduction, which is a mitigation strategy but not the primary 'allocation' solution for ensuring fairness and equity among stakeholders as discussed. This question assesses the ability to infer the most appropriate policy response from the given context, a key skill for UPSC CSAT.

Question 32Permanent link
Which one the following statements best reflects what is implied by the passage?
  1. A. Education system must be strengthened in rural areas.
  2. B. Large scale and effective implementation of skill development programme is the need of the hour.
  3. C. For economic development, health and nutrition of only skilled workers needs special attention.
  4. D. For rapid economic growth as envisaged by us, attention should be paid to health and nutrition of the people.
Show answer and explanation

Answer: D

Explanation

The passage details how widespread health issues like anaemia and tuberculosis reduce productivity, and how malnutrition in children impairs cognitive ability, posing a challenge for an economy needing skilled workers. The overarching message is that poor health and nutrition undermine both current productivity and future potential, directly impacting economic development. Option (D) accurately captures this by stating that 'attention should be paid to health and nutrition of the people' for rapid economic growth. Options (A) and (B) introduce topics (education system, skill development) not directly discussed as the primary implication. Option (C) is too narrow, as the passage discusses health impacts on working-age adults and children generally, not just skilled workers. This question assesses the ability to grasp the central theme and implication of the passage, a crucial skill for CSAT.

Question 33Permanent link
Which one of the following statements best reflects the most logical and rational message conveyed by the author of the passage?
  1. A. Adaptation to climate change and mitigation response are basically the responsibilities of the government.
  2. B. Climate change causes a change in government policies regarding land use patterns in the country.
  3. C. Risk perceptions of farmers are important for motivating them for taking adaptation decisions.
  4. D. Since mitigation is not possible, governments should come up with policies for quick response to climate change.
Show answer and explanation

Answer: C

Explanation

The passage discusses the challenges faced by marginal farmers in adapting to climate change, highlighting their low adaptive capabilities and the need for planned, policy-driven adaptation. Crucially, it states, 'Perception is a necessary pre-requisite for adaptation. Whether farmers are adapting agricultural practices to climate change depends on whether they perceive it or not. However, this is not always enough for adaptation. It is important how a farmer perceives the risks associated with climate change.' This directly supports option (C), emphasizing the importance of farmers' risk perceptions. Option (A) is too strong; while government intervention is suggested, it doesn't state these are *solely* government responsibilities. Option (B) introduces land use patterns, which are not the central theme. Option (D) incorrectly states that mitigation is not possible; the passage mentions 'fast mitigation response' alongside adaptation. This question requires identifying the most accurate summary of the author's key message, a common task in CSAT reading comprehension.

Question 34Permanent link
Raj has ten pairs of red, nine pairs of white and eight pairs of black shoes in a box. If he randomly picks shoes one by one (without replacement) from the box to get a red pair of shoes to wear, what is the maximum number of attempts he has to make?
  1. A. 27
  2. B. 36
  3. C. 44
  4. D. 45
Show answer and explanation

Answer: D

Explanation

This is a worst-case scenario problem. To guarantee a red pair, Raj must first pick all shoes that are not red, and then enough red shoes to ensure a pair (one left, one right). There are 10 pairs of red (20 shoes), 9 pairs of white (18 shoes), and 8 pairs of black (16 shoes). In the worst case, Raj would first pick all the white shoes (18 attempts) and all the black shoes (16 attempts). This totals 18 + 16 = 34 shoes, none of which are red. At this point, only red shoes remain in the box. To guarantee a red pair, he could then pick all 10 left red shoes (worst case, assuming he picks all of one type first). The very next shoe he picks (the 11th red shoe) must be a right red shoe, completing a pair. So, the maximum number of attempts = 34 (non-red shoes) + 10 (all left red shoes) + 1 (one right red shoe) = 45 attempts. This question tests logical thinking and the application of the worst-case scenario principle, a common type in CSAT.

Question 35Permanent link
In how many ways can a batsman score exactly 25 runs by scoring single runs, fours and sixes only, irrespective of the sequence of scoring shots?
  1. A. 18
  2. B. 19
  3. C. 20
  4. D. 21
Show answer and explanation

Answer: B

Explanation

Let x be the number of singles, y be the number of fours, and z be the number of sixes. The problem requires finding the number of non-negative integer solutions to the equation x + 4y + 6z = 25. We can systematically find combinations by iterating through possible values of z (number of sixes):
1. If z = 0: x + 4y = 25. Possible (x, y) pairs are (1, 6), (5, 5), (9, 4), (13, 3), (17, 2), (21, 1), (25, 0). (7 ways)
2. If z = 1: x + 4y = 19. Possible (x, y) pairs are (3, 4), (7, 3), (11, 2), (15, 1), (19, 0). (5 ways)
3. If z = 2: x + 4y = 13. Possible (x, y) pairs are (1, 3), (5, 2), (9, 1), (13, 0). (4 ways)
4. If z = 3: x + 4y = 7. Possible (x, y) pairs are (3, 1), (7, 0). (2 ways)
5. If z = 4: x + 4y = 1. Possible (x, y) pair is (1, 0). (1 way)
For z ≥ 5, 6z would be 30 or more, exceeding 25, so no solutions exist. Summing the ways from each case: 7 + 5 + 4 + 2 + 1 = 19 ways. This question tests basic combinatorics and systematic enumeration, a common type in CSAT.

Question 36Permanent link
There are four letters and four envelopes and exactly one letter is to be put in exactly one envelope with the correct address. If the letters are randomly inserted into the envelopes, then consider the following statements: 1. It is possible that exactly one letter goes into an incorrect envelope. 2. There are only six ways in which only two letters can go into the correct envelopes. Which of the statements given above is/are correct?
  1. A. 1 only
  2. B. 2 only
  3. C. Both 1 and 2
  4. D. Neither 1 nor 2
Show answer and explanation

Answer: B

Explanation

This problem involves permutations and derangements.
Statement 1: 'It is possible that exactly one letter goes into an incorrect envelope.' If one letter is in an incorrect envelope, say Letter A is in Envelope B, then Envelope A cannot contain Letter A. It must contain some other letter (B, C, or D). This means at least two letters must be misplaced. It's impossible for only one letter to be misplaced while all others are correctly placed. Thus, Statement 1 is incorrect.
Statement 2: 'There are only six ways in which only two letters can go into the correct envelopes.' We need to choose 2 letters out of 4 to be placed correctly. This can be done in C(4, 2) ways = 6 ways. For the remaining 2 letters, they must be placed in incorrect envelopes (deranged). The number of derangements for 2 items, D(2), is 1 (they must swap positions). So, the total number of ways is C(4, 2) * D(2) = 6 * 1 = 6 ways. Thus, Statement 2 is correct. This question tests understanding of permutations, combinations, and derangements, which are relevant for CSAT.

Question 37Permanent link
What is the remainder when 85 × 87 × 89 × 91 × 95 × 96 is divided by 100?
  1. B. 1
  2. C. 2
  3. D. 4
Show answer and explanation

Answer: A

Explanation

To find the remainder when a product is divided by 100, we need to check for factors of 100 (which are 25 and 4). The given product is 85 × 87 × 89 × 91 × 95 × 96. Let's identify factors of 5 and 2 within these numbers:
- 85 contains a factor of 5 (85 = 5 × 17).
- 95 contains a factor of 5 (95 = 5 × 19).
So, we have two factors of 5, which multiply to 25.
- 96 contains a factor of 4 (96 = 4 × 24).
Since the product contains factors of both 25 and 4, it means the entire product is divisible by 25 × 4 = 100. When a number is completely divisible by another number, the remainder is 0. This question tests basic number theory concepts related to divisibility and remainders, a fundamental part of CSAT quantitative aptitude.

Question 38Permanent link
What is the unit digit in the expansion of (57242) 9×7×5×3×1 ?
  1. A. 2
  2. B. 4
  3. C. 6
  4. D. 8
Show answer and explanation

Answer: A

Explanation

To find the unit digit of a number raised to a power, we only need to consider the unit digit of the base number and the cyclicity of its powers. The unit digit of the base number (57242) is 2. The exponent is 9 × 7 × 5 × 3 × 1 = 945. The cyclicity of the unit digit of powers of 2 is: 2^1 = 2, 2^2 = 4, 2^3 = 8, 2^4 = 16 (unit digit 6), 2^5 = 32 (unit digit 2). The cycle length is 4 (2, 4, 8, 6). To find the unit digit, we divide the exponent (945) by the cycle length (4) and use the remainder. 945 ÷ 4 gives a remainder of 1 (since 945 = 4 × 236 + 1). Therefore, the unit digit of (57242)^945 will be the same as the unit digit of 2^1, which is 2. This question assesses knowledge of number properties, specifically unit digits and cyclicity, a common topic in CSAT.

Question 39Permanent link
If ABC and DEF are both 3-digit numbers such that A, B, C, D, E, and F are distinct non-zero digits such that ABC+ DEF= 1111, then what is the value of A+B+C+D+E+F ?
  1. A. 28
  2. B. 29
  3. C. 30
  4. D. 31
Show answer and explanation

Answer: D

Explanation

We are given ABC + DEF = 1111, where A, B, C, D, E, F are distinct non-zero digits. Let's analyze the addition column by column:
1. Units place: C + F must result in a unit digit of 1. Since C and F are distinct non-zero digits, C + F = 11 (with a carry of 1 to the tens place).
2. Tens place: B + E + (carry 1) = 11. So, B + E = 10 (with a carry of 1 to the hundreds place).
3. Hundreds place: A + D + (carry 1) = 11. So, A + D = 10.
We need to find distinct non-zero digits for A, B, C, D, E, F that satisfy these conditions. One possible set of assignments is:
- C + F = 11: Let C=2, F=9.
- B + E = 10: Using remaining digits, let B=3, E=7.
- A + D = 10: Using remaining digits, let A=4, D=6.
All digits (2, 9, 3, 7, 4, 6) are distinct and non-zero. Let's verify: 432 + 679 = 1111. This works. The sum A+B+C+D+E+F = 4+3+2+6+7+9 = 31. Any valid combination of distinct non-zero digits satisfying the sums will yield the same total sum. This question tests logical deduction and number properties, a typical CSAT problem.

Question 40Permanent link
D is a 3-digit number such that the ratio of the number to the sum of its digits is least. What is the difference between the digit at the hundred's place and the digit at the unit's place of D?
  1. B. 7
  2. C. 8
  3. D. 9
Show answer and explanation

Answer: C

Explanation

Let the 3-digit number be 100X + 10Y + Z. The sum of its digits is X + Y + Z. We want to minimize the ratio (100X + 10Y + Z) / (X + Y + Z). To minimize this ratio, we generally look for numbers where the hundreds digit (X) is small, and the sum of digits (X+Y+Z) is large. Let's test numbers starting with the smallest possible hundreds digit, X=1:
- For 100, ratio = 100 / (1+0+0) = 100.
- For 109, ratio = 109 / (1+0+9) = 10.9.
- For 119, ratio = 119 / (1+1+9) = 10.81.
- For 199, ratio = 199 / (1+9+9) = 199/19 ≈ 10.47.
If we try numbers with X=2, e.g., 299, the ratio is 299 / (2+9+9) = 299/20 = 14.95, which is higher than 10.47. As the hundreds digit increases, the numerator grows much faster than the denominator, so the ratio will increase. Thus, the number D that yields the least ratio is 199. For D=199, the digit at the hundred's place is 1, and the digit at the unit's place is 9. The difference between these digits is |1 - 9| = 8. This question requires numerical reasoning and systematic testing, a common type in CSAT.

Question 41Permanent link
Which one of the following statements most likely reflects as to what the author of the passage intends to say?
  1. A. Enrolment in schools and colleges is high but there is no quality education.
  2. B. Unemployment must be seen as a function of rising education and aspirations of young Indians.
  3. C. There are no labour-intensive industries to accommodate the huge number of unemployed people.
  4. D. The education system should be properly designed so as to enable the educated people to be self-employed.
Show answer and explanation

Answer: B

Explanation

The passage argues that the unemployment rate in India is skewed by rising education levels and the aspirations of younger, more educated individuals. It explicitly states that 'rising education levels inflate unemployment challenges' and that younger Indians 'exhibit greater willingness to wait for the right job.' This directly supports option (B), which links unemployment to 'rising education and aspirations of young Indians.' Options (A), (C), and (D) introduce external factors like quality of education, lack of labour-intensive industries, or specific education system design, which are not directly discussed or implied by the passage as the author's primary message. This question tests the ability to identify the central argument or implication of the text, a key skill for CSAT.

Question 42Permanent link
Which one of the following statements best reflects the most rational, logical and practical message conveyed by the passage?
  1. A. Modern statesmen need to be well trained in scientific methods and philosophical thinking to enable them to have a better perspective of their roles, responsibilities and goals.
  2. B. It is not desirable to have Governments managed by empirical statesmen unless well mixed with others who are grounded in learning and reflect wisdom.
  3. C. As the statesmen/bureaucrats are the products of a society, it is desirable to have a system of education in a society that focuses on training its citizens in scientific method and philosophical thinking from a very early age.
  4. D. It is desirable that all scientists need to be philosophers as well to make their work goal- oriented and thus purposeful and useful to the society.
Show answer and explanation

Answer: B

Explanation

The passage draws an analogy between science needing philosophy and government needing statesmanship (guided by total knowledge and perspective). It explicitly states, 'Government suffers, precisely like science, for lack of philosophy' and that 'the pursuit of politics becomes a destructive bedlam when divorced from science and philosophy.' This implies that a purely empirical, fact-driven approach in governance, without the guiding principles and wisdom of philosophy, is detrimental. Option (B) captures this by suggesting that governments should not be managed *solely* by empirical statesmen but should be 'well mixed with others who are grounded in learning and reflect wisdom.' This aligns with the passage's call for a broader, philosophical perspective in governance. Options (A), (C), and (D) propose specific training or universal roles which, while potentially beneficial, are not the direct, most rational, logical, and practical message conveyed by the passage's analogy and critique. This question requires a nuanced understanding of the analogy presented, a challenging aspect of CSAT comprehension.

Question 43Permanent link
Based on the above passage, which one of the following terms expresses the ultimate goal of the state?
  1. A. Personal safety
  2. B. Health of body and mind
  3. C. Communal harmony
  4. D. Liberty
Show answer and explanation

Answer: D

Explanation

The passage describes the ultimate goal of the state as freeing individuals from fear, enabling them to live with security, and crucially, to 'lead men to live by, and to exercise, a free reason.' While personal safety, health of body and mind, and communal harmony are mentioned as components or consequences, the overarching theme of 'free reason' and acting without restraint (other than not injuring others) points directly to the concept of liberty. The state's role is to create conditions where individuals can exercise their freedom responsibly. Liberty encompasses the ability to act freely, think rationally, and live securely without undue fear or domination, which is the essence of the passage's message. This question tests the ability to synthesize various elements into a single, overarching concept, a common requirement in CSAT reading comprehension.

Question 44Permanent link
What is the remainder if 2^192 is divided by 6?
  1. B. 1
  2. C. 2
  3. D. 4
Show answer and explanation

Answer: D

Explanation

To find the remainder when 2^192 is divided by 6, we can observe the pattern of remainders of powers of 2 when divided by 6:
2^1 = 2 (Remainder 2)
2^2 = 4 (Remainder 4)
2^3 = 8 (Remainder 2)
2^4 = 16 (Remainder 4)
The pattern of remainders is 2, 4, 2, 4... We observe that if the power of 2 is odd, the remainder is 2; if the power of 2 is even (and greater than or equal to 2), the remainder is 4. Since the power 192 is an even number, the remainder when 2^192 is divided by 6 will be 4. This question tests number theory concepts, specifically remainders and cyclicity, which are common in CSAT.

Question 45Permanent link
Consider the sequence ABC_ _ABC_DABBCD_ABCD that follows a certain pattern. Which of the following completes the sequence?
  1. A. DACB
  2. B. CDAB
  3. C. DCCA
  4. D. DDCA
Show answer and explanation

Answer: D

Explanation

The given sequence is ABC_ _ABC_DABBCD_ABCD. Let's analyze the pattern by dividing the sequence into blocks of 4 or 5 characters. The provided solution suggests a cyclic shift pattern when divided into blocks of 4, where the last character of a block moves to the first position of the next block. If we assume the complete sequence follows the pattern: ABCD, DABC, CDAB, BCDA, ABCD. Let's map this to the given sequence with blanks:
1. ABC_ -> ABCD (Blank is D)
2. _ABC -> DABC (Blank is D)
3. _DAB -> CDAB (Blank is C)
4. BCD_ -> BCDA (Blank is A)
5. ABCD -> ABCD (No blank)
So, the missing letters are D, D, C, A. This matches option (D). The pattern is a cyclic shift of the letters A, B, C, D. This question tests pattern recognition in sequences, a common logical reasoning topic in CSAT.

Question 46Permanent link
AB and CD are 2-digit numbers. Multiplying AB with CD results in a 3-digit number DEF. Adding DEF to another 3-digit number GHI results in 975. Further A, B, C, D. E, F, G, H, I are distinct digits. If E= 0, F=8, then what is A+B+C equal to?
  1. A. 6
  2. B. 7
  3. C. 8
  4. D. 9
Show answer and explanation

Answer: A

Explanation

We are given: 1) AB × CD = DEF, 2) DEF + GHI = 975, and A, B, C, D, E, F, G, H, I are distinct digits. Also, E=0 and F=8. Substituting E=0, F=8 into DEF + GHI = 975 gives D08 + GHI = 975.
From the units column: 8 + I = 15 (since I is a digit), so I=7 (carry 1).
From the tens column: 0 + H + 1 (carry) = 7, so H=6.
From the hundreds column: D + G = 9.
Used digits so far: E=0, F=8, I=7, H=6. Remaining digits for D, G are from {1,2,3,4,5,9}. Possible (D,G) pairs summing to 9 are (4,5) or (5,4).
Now consider AB × CD = DEF, which is AB × C_ = D08. If D=5, then AB × C_ = 508. A number ending in 5 (C5) multiplied by any number cannot result in a product ending in 8. So D cannot be 5. Thus, D=4 and G=5. So DEF = 408.
Now we have AB × C_ = 408. Used digits: 0, 4, 5, 6, 7, 8. Remaining for A, B, C are {1,2,3,9}. Since C_ is a 2-digit number ending in 4, C must be one of {1,3,9}. Also, B must be 2 (since _2 * _4 ends in 8). So B=2.
Now, A2 × C4 = 408. If C=1, A2 × 14 = 408 => A2 = 29.14 (not integer). If C=3, A2 × 34 = 408 => A2 = 12. This works! So A=1, B=2, C=3. All digits {1,2,3,4,0,8,5,6,7} are distinct. Therefore, A+B+C = 1+2+3 = 6. This is a complex number puzzle requiring careful deduction, typical of CSAT.

Question 47Permanent link
Consider the following statements in respect of five candidates P, Q, R, S, and T. Two statements are true and one statement is false. True Statement: One of P and Q was selected for the job. False Statement: At least one of R and S was selected for the job. True Statement: At most two of R, S and T were selected for the job. Which of the following conclusions can be drawn? 1. At least four were selected for the job. 2. S was selected for the job. Select the correct answer using the code given below:
  1. A. 1 only
  2. B. 2 only
  3. C. Both 1 and 2
  4. D. Neither 1 nor 2
Show answer and explanation

Answer: D

Explanation

Let's analyze the given statements:
1. True Statement 1: 'One of P and Q was selected.' This means exactly one of P or Q is selected.
2. False Statement: 'At least one of R and S was selected.' Since this is false, its negation is true: 'Neither R nor S was selected.' So, R is NOT selected and S is NOT selected.
3. True Statement 2: 'At most two of R, S and T were selected.' This means the number of selected candidates from {R, S, T} is 0, 1, or 2.
Combining these deductions:
- From (2), R and S are not selected (0 candidates from R, S).
- From (1), exactly one of P or Q is selected (1 candidate).
- From (3), since R and S are not selected, this statement implies that at most two of T were selected. As there is only one T, this means T can either be selected or not selected (0 or 1 candidate from T).
Therefore, the total number of selected candidates can be 1 (if T is not selected) or 2 (if T is selected).
Now, evaluate the conclusions:
Conclusion 1: 'At least four were selected for the job.' This is incorrect, as a maximum of 2 candidates can be selected.
Conclusion 2: 'S was selected for the job.' This is incorrect, as we deduced that S was NOT selected.
Thus, neither Conclusion 1 nor Conclusion 2 follows. This question tests logical deduction and careful interpretation of quantifiers, a common challenge in CSAT.

Question 48Permanent link
Let P, Q, R, S and T be five statements such that: I. If P is true, then both Q and S are true. II. If R and S are true, then T is false. Which of the following can be concluded? 1. If T is true, then at least one of P and R must be false. 2. If Q is true, then P is true. Select the correct answer using the code given below:
  1. A. 1 Only
  2. B. 2 Only
  3. C. Both 1 and 2
  4. D. Neither 1 nor 2
Show answer and explanation

Answer: A

Explanation

Let's translate the given statements into logical notation:
I. P → (Q ∧ S) (If P is true, then Q and S are true)
II. (R ∧ S) → ¬T (If R and S are true, then T is false)
Now, let's evaluate the conclusions:
Conclusion 1: 'If T is true, then at least one of P and R must be false.' This is equivalent to T → (¬P ∨ ¬R).
From statement II, the contrapositive is T → ¬(R ∧ S), which simplifies to T → (¬R ∨ ¬S). So, if T is true, then R is false OR S is false.
From statement I, the contrapositive is ¬(Q ∧ S) → ¬P, which simplifies to (¬Q ∨ ¬S) → ¬P. So, if Q is false OR S is false, then P is false.
If T is true, then (¬R ∨ ¬S). If ¬S is true, then from the contrapositive of I, ¬P is true. So, if T is true, then (¬R ∨ ¬P) is true, meaning at least one of P and R must be false. Thus, Conclusion 1 is correct.
Conclusion 2: 'If Q is true, then P is true.' (Q → P)
Statement I is P → (Q ∧ S). This means P implies Q, but Q does not necessarily imply P. If Q is true, P could still be false (e.g., Q is true, S is true, but P is false). Thus, Conclusion 2 is incorrect.
Therefore, only Conclusion 1 follows. This question tests a deep understanding of conditional logic and contrapositives, a challenging aspect of CSAT.

Question 49Permanent link
A cuboid of dimensions 7cm × 5cm × 3cm is painted red, green and blue colour on each pair of opposite faces of dimensions 7cm × 5cm × 5cm, 5cm × 3cm, 7cm × 3cm respectively. Then the cuboid is cut and separated into various cubes each of side length 1cm. Which of the following statements is/are correct? 1. There are exactly 15 small cubes with no paint on any face. 2. There are exactly 6 small cubes with exactly two faces, one painted with blue and the other with green. Select the correct answer using the code given below:
  1. A. 1 Only
  2. B. 2 Only
  3. C. Both 1 and 2
  4. D. Neither 1 nor 2
Show answer and explanation

Answer: A

Explanation

The cuboid has dimensions L=7cm, W=5cm, H=3cm. It is cut into 1cm cubes.
Statement 1: 'There are exactly 15 small cubes with no paint on any face.' Unpainted cubes are the inner cubes. Their dimensions are (L-2) × (W-2) × (H-2). Number of unpainted cubes = (7-2) × (5-2) × (3-2) = 5 × 3 × 1 = 15. So, Statement 1 is correct.
Statement 2: 'There are exactly 6 small cubes with exactly two faces, one painted with blue and the other with green.' The faces are painted as follows: 7x5 faces (Red), 5x3 faces (Green), 7x3 faces (Blue). Cubes with exactly two faces painted blue and green must be along the edges where a blue face and a green face meet. These are the edges of length 3cm (where the 7x3 face meets the 5x3 face). A cuboid has 4 such edges. For an edge of length 'n' cm, the number of cubes with exactly two painted faces (excluding corner cubes) is (n-2). So, for each 3cm edge, the number of cubes with two painted faces (blue and green) = (3-2) = 1. Since there are 4 such edges, the total number of such cubes = 4 × 1 = 4. The statement claims there are 6 such cubes, which is incorrect. Therefore, only Statement 1 is correct. This question tests spatial reasoning and visualization of 3D objects, a common type in CSAT.

Question 50Permanent link
The letters of the word "INCOMPREHENSIBILITIES" are arranged alphabetically in reverse order. How many positions of the letter/letters will remain unchanged?
  1. A. None
  2. B. One
  3. C. Two
  4. D. Three
Show answer and explanation

Answer: C

Explanation

The given word is INCOMPREHENSIBILITIES. First, list all the letters and their counts: I (5), N (2), C (1), O (1), M (1), P (1), R (1), E (3), H (1), B (1), L (1), S (2), T (1). Total letters: 21. Now, arrange these letters alphabetically in reverse order (from Z to A): T S S R P O N N M L I I I I I H E E E C B. Let's compare the original word with the reverse alphabetically sorted sequence, position by position:
Original: I N C O M P R E H E N S I B I L I T I E S
Position: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
Sorted: T S S R P O N N M L I I I I I H E E E C B
Comparing the letters at each position, we find matches at:
- Position 13: Original 'I', Sorted 'I'. (Match)
- Position 15: Original 'I', Sorted 'I'. (Match)
All other positions have different letters. Therefore, exactly two positions of the letters remain unchanged. This question tests attention to detail and systematic comparison, a common type of logical reasoning problem in CSAT.

Question 51Permanent link
Which one of the following statements best reflects the most logical message implied by the above passage?
  1. A. Modern technology enfeebles societal structure and makes life difficult.
  2. B. Modern life is full of uncertainties and endless difficult choices.
  3. C. We are influenced by the opinion of others and have no courage to follow our own convictions.
  4. D. In our lives, having too few choices may not be a good thing, but having too many can be equally as difficult.
Show answer and explanation

Answer: D

Explanation

The passage introduces 'the paradox of choice' using Buridan's ass, where an abundance of equally appealing options leads to paralysis. It then extends this to modern life, where technology 'exacerbate[s] our glut of choices,' making decisions more difficult and leading to unhappiness and anxiety despite attractive options. The core message is that while choices are fundamental, an *excess* of choices can be detrimental. Option (D) perfectly encapsulates this 'paradox of choice' by stating that 'having too few choices may not be a good thing, but having too many can be equally as difficult.' Options (A), (B), and (C) either misrepresent the passage's focus or introduce elements not discussed (societal structure, external influence). This question tests the ability to identify the central theme and implied message of the passage, a key skill for CSAT.

Question 52Permanent link
Regarding the financialization of household savings, which of the following statements best reflect the solutions that are implied by the passage? 1. A flexible environment is needed to develop solutions. 2. Households need customized solutions. 3. Innovations in financial technology are required. Select the correct answer using the code given below:
  1. A. 1 and 2 only
  2. B. 2 and 3 only
  3. C. 1 and 3 only
  4. D. 1, 2 and 3
Show answer and explanation

Answer: A

Explanation

The passage discusses challenges in financializing household savings in India, listing 'onerous bureaucracy,' 'scepticism of organized financial institutions,' and 'a lack of basic information about which of the myriad services and providers is best for each family' as hurdles.
1. 'A flexible environment is needed to develop solutions.' The mention of 'onerous bureaucracy' implies a rigid, difficult environment. To overcome this, a flexible environment would be necessary. So, statement 1 is implied.
2. 'Households need customized solutions.' The phrase 'a lack of basic information about which of the myriad services and providers is best for each family' directly suggests that generic solutions are not sufficient and families need tailored advice or products. So, statement 2 is implied.
3. 'Innovations in financial technology are required.' While FinTech could potentially address some issues, the passage does not explicitly mention or imply that *innovations in financial technology* are a required solution. It focuses more on systemic issues (bureaucracy, trust) and information gaps, rather than technological advancement itself. So, statement 3 is not directly implied.
Therefore, only statements 1 and 2 are implied. This question tests the ability to infer solutions from identified problems within the text, a common CSAT skill.

Question 53Permanent link
Based on the above passage, the following assumptions have been made: 1. Patent protection given to patentees puts a huge burden on public's purchasing power in accessing patented medicines. 2. Dependence on other countries for pharmaceutical products is a huge burden for developing and poor countries. 3. Providing medicines to the public at affordable prices is a key goal during the public health policy design in many countries. 4. Governments need to find and appropriate balance between the rights of patentees and the requirements of the patients. Which of the above assumptions are valid?
  1. A. 1 and 2
  2. B. 1 and 4
  3. C. 3 and 4
  4. D. 2 and 3
Show answer and explanation

Answer: B

Explanation

Let's evaluate each assumption based on the passage:
1. 'Patent protection given to patentees puts a huge burden on public's purchasing power in accessing patented medicines.' The passage states, 'The patentees enjoy the liberty to determine the price of medicines... which... could be unaffordable to the public.' This directly supports the assumption that high prices burden public purchasing power. So, assumption 1 is valid.
2. 'Dependence on other countries for pharmaceutical products is a huge burden for developing and poor countries.' The passage discusses patents and their impact on prices and R&D within a country's context. It does not mention international dependence. So, assumption 2 is not valid based on the passage.
3. 'Providing medicines to the public at affordable prices is a key goal during the public health policy design in many countries.' While generally true, the passage focuses on the *consequences* of patent protection (high prices vs. R&D benefits) rather than explicitly stating this as a *goal* of public health policy design. It's external knowledge, not an assumption *made by the passage*. So, assumption 3 is not directly valid from the passage.
4. 'Governments need to find an appropriate balance between the rights of patentees and the requirements of the patients.' The passage highlights the 'cost, in the nature of higher prices for patented medicine' versus the 'benefit the public over the longer term through innovations and research and development (R&D).' This inherent tension implies a need for balance, which governments would be responsible for. So, assumption 4 is valid.
Therefore, assumptions 1 and 4 are valid. This question tests the ability to identify direct and indirect assumptions made within the text, a critical skill for CSAT.

Question 54Permanent link
Based on the above passage, the following assumptions have been made: 1. Protection of privacy is not just a right, but it has value to the economy. 2. There is a fundamental link between privacy and innovation. Which of the above assumptions is/are valid?
  1. A. 1 only
  2. B. 2 only
  3. C. Both 1 and 2
  4. D. Neither 1 nor 2
Show answer and explanation

Answer: C

Explanation

Let's evaluate each assumption based on the passage:
1. 'Protection of privacy is not just a right, but it has value to the economy.' The passage states, 'The ultimate control of data must reside with the individuals who generate it; they should be enabled to use, restrict or monetize it as they wish.' The ability to 'monetize' data implies an economic value. Furthermore, the opening sentence links 'growth of the digital economy' with 'keeping personal data... secure and protected,' suggesting privacy protection contributes to economic growth. So, assumption 1 is valid.
2. 'There is a fundamental link between privacy and innovation.' The passage explicitly states, 'No one will innovate in a surveillance-oriented environment or in a place where an individual's personal information is compromised.' It concludes that 'data protection laws should enable the right kind of innovation – one that is user-centric and privacy protecting.' This directly establishes a fundamental link between privacy and the fostering of innovation. So, assumption 2 is valid.
Therefore, both assumptions 1 and 2 are valid. This question tests the ability to identify direct and indirect assumptions made within the text, a critical skill for CSAT.

Question 55Permanent link
In an examination, the maximum marks for each of the four papers namely P, Q, R and S are 100. Marks scored by the students are in integers. A student can score 99% in n different ways. What is the value of n?
  1. A. 16
  2. B. 17
  3. C. 23
  4. D. 35
Show answer and explanation

Answer: D

Explanation

The total maximum marks for the four papers (P, Q, R, S) is 4 * 100 = 400. A student scores 99% of the total marks, which is 0.99 * 400 = 396 marks. This means the student lost a total of 400 - 396 = 4 marks across the four papers. Let p, q, r, and s be the marks lost in papers P, Q, R, and S, respectively. Since marks scored are integers, marks lost must also be non-negative integers. The sum of marks lost is p + q + r + s = 4. Also, since each paper has a maximum of 100 marks, the marks lost in any single paper cannot exceed 4 (e.g., if 5 marks were lost in one paper, the score would be 95, and even if other papers were 100, the total would be 395, less than 396). This problem is a classic 'stars and bars' problem, finding the number of non-negative integer solutions to x1 + x2 + ... + xk = n. Here, n=4 (total marks lost) and k=4 (number of papers). The number of ways is C(n + k - 1, k - 1) = C(4 + 4 - 1, 4 - 1) = C(7, 3). C(7, 3) = (7 × 6 × 5) / (3 × 2 × 1) = 35. This question tests combinatorics, specifically the stars and bars method, a common advanced topic in CSAT.

Question 56Permanent link
A flag has to be designed with 4 horizontal strips using some or all of the colours red, green and yellow. What is the number of different ways in which this can be done so that no two adjacent stripes have the same colour?
  1. A. 12
  2. B. 18
  3. C. 24
  4. D. 36
Show answer and explanation

Answer: C

Explanation

We need to design a flag with 4 horizontal stripes using three colors (red, green, yellow), such that no two adjacent stripes have the same color. Let's determine the number of choices for each stripe:
1. For the first stripe: There are 3 available colors (Red, Green, Yellow). So, 3 choices.
2. For the second stripe: It must be different from the first stripe. This leaves 2 choices.
3. For the third stripe: It must be different from the second stripe. This again leaves 2 choices (it can be the same color as the first stripe, but not the second).
4. For the fourth stripe: It must be different from the third stripe. This also leaves 2 choices.
To find the total number of different ways, we multiply the number of choices for each stripe: 3 × 2 × 2 × 2 = 24 ways. This question tests basic principles of permutations and combinations with restrictions, a common topic in CSAT.

Question 57Permanent link
A rectangular floor measures 4 m in length and 2.2m in breadth. Tiles of size 140 cm by 60 cm have to be laid such that the tiles do not overlap. A tile can be placed in any orientation so long as its edges are parallel to the edges of the floor. What is the maximum number of tiles that can be accommodated on the floor?
  1. A. 6
  2. B. 7
  3. C. 8
  4. D. 9
Show answer and explanation

Answer: C

Explanation

The floor dimensions are 4 m = 400 cm in length and 2.2 m = 220 cm in breadth. The tiles are 140 cm by 60 cm. We need to find the maximum number of tiles that can be accommodated, considering both orientations.
Consider placing tiles with their 140 cm side along the 400 cm length and 60 cm side along the 220 cm breadth:
- Along length: 400 cm / 140 cm = 2 tiles (280 cm used). Remaining length = 120 cm.
- Along breadth: 220 cm / 60 cm = 3 tiles (180 cm used). Remaining breadth = 40 cm.
This initial placement covers 2 × 3 = 6 tiles. The remaining area is a 120 cm × 220 cm strip and a 400 cm × 40 cm strip. Let's focus on the 120 cm × 220 cm strip. In this area, we can place tiles with their 60 cm side along the 120 cm length (120/60 = 2 tiles) and their 140 cm side along the 220 cm breadth (220/140 = 1 tile). This fits 2 × 1 = 2 more tiles. Total tiles = 6 + 2 = 8 tiles. Other arrangements or trying to fit into the 400 cm × 40 cm strip will not yield more tiles. For example, if we place tiles with 60 cm side along 400 cm length (400/60 = 6 tiles) and 140 cm side along 220 cm breadth (220/140 = 1 tile), we get 6 tiles, with a remaining 40 cm × 220 cm area where no full tile can fit. Thus, the maximum number of tiles is 8. This question tests practical application of mensuration and optimization, requiring careful consideration of orientations and remaining space, a challenging aspect of CSAT.

Question 58Permanent link
There are five persons, P, Q, R, S and T each one of whom has to be assigned one task. Neither P nor Q can be assigned Task-1. Task-2 must be assigned to either R or S. In how many ways can the assignment be done?
  1. A. 6
  2. B. 12
  3. C. 18
  4. D. 24
Show answer and explanation

Answer: D

Explanation

We have 5 persons (P, Q, R, S, T) and 5 tasks (Task-1 to Task-5). Each person is assigned one task, and each task is assigned to one person.
Conditions:
1. Neither P nor Q can be assigned Task-1.
2. Task-2 must be assigned to either R or S.
Let's break this into two cases based on Condition 2:
Case 1: Task-2 is assigned to R.
- Task-2: R (1 way).
- Task-1: Cannot be P, Q, or R (since R is taken). So, Task-1 can be assigned to S or T (2 ways).
- Remaining 3 persons (P, Q, and the one not assigned to Task-1) can be assigned to the remaining 3 tasks in 3! = 6 ways.
Total ways for Case 1 = 1 × 2 × 6 = 12 ways.
Case 2: Task-2 is assigned to S.
- Task-2: S (1 way).
- Task-1: Cannot be P, Q, or S (since S is taken). So, Task-1 can be assigned to R or T (2 ways).
- Remaining 3 persons (P, Q, and the one not assigned to Task-1) can be assigned to the remaining 3 tasks in 3! = 6 ways.
Total ways for Case 2 = 1 × 2 × 6 = 12 ways.
Total number of ways = Ways in Case 1 + Ways in Case 2 = 12 + 12 = 24 ways. This question tests permutations and combinations with multiple constraints, a common type in CSAT.

Question 59Permanent link
There are large number of silver coins weighing 2gm, 5gm, 10gm, 25gm, 50gm each. Consider the following statements: 1. To buy 78 gm of coins one must buy at least 7 coins. 2. To weigh 78 gm using these coins one can use less than 7 coins. Which of the statements given above is/are correct?
  1. A. 1 only
  2. B. 2 only
  3. C. Both 1 and 2
  4. D. Neither 1 nor 2
Show answer and explanation

Answer: C

Explanation

Coin denominations: 2gm, 5gm, 10gm, 25gm, 50gm.
Statement 1: 'To buy 78 gm of coins one must buy at least 7 coins.' To minimize the number of coins, we use the largest denominations first. To make 78gm:
- One 50gm coin (1 coin). Remaining: 28gm.
- Two 10gm coins (2 coins, 20gm). Remaining: 8gm.
- Four 2gm coins (4 coins, 8gm). Remaining: 0gm.
Total coins = 1 + 2 + 4 = 7 coins. It's not possible to make 78gm with fewer than 7 coins using only addition. So, Statement 1 is correct.
Statement 2: 'To weigh 78 gm using these coins one can use less than 7 coins.' This implies using a balance scale where coins can be placed on both pans. To weigh 78gm, we can place the object on one pan. On the other pan, place coins that sum to slightly more than 78gm, and then add coins to the object's pan to balance. For example:
- Place 50gm + 25gm + 5gm = 80gm on one pan (3 coins).
- Place the 78gm object on the other pan. The 80gm pan is 2gm heavier.
- Add one 2gm coin to the pan with the 78gm object to balance it (1 coin).
Total coins used = 3 (on one side) + 1 (on the other side) = 4 coins. Since 4 is less than 7, Statement 2 is correct. This question tests careful reading of 'buy' vs 'weigh' and understanding of balance scales, a challenging aspect of CSAT.

Question 60Permanent link
Consider the following: I. A + B means A is neither smaller nor equal to B. II. A – B means A is not greater than B. III A × B means A is not smaller than B. IV. A ÷ B means A is neither greater nor equal to B. V. A ± B means A is neither smaller nor greater than B. Statement: P × Q, P – T, T ÷ R, R ± S Conclusion-1: Q ± T Conclusion-2: S+Q Which one of the following is correct in respect of the above Statement and the Conclusions?
  1. A. Only Conclusion-1 follows from the Statement.
  2. B. Only Conclusion-2 follows from the Statement.
  3. C. Both Conclusion-1 and Conclusion-2 follow from the Statement.
  4. D. Neither Conclusion-1 nor Conclusion-2 follows from the Statement.
Show answer and explanation

Answer: B

Explanation

First, let's decode the symbols into standard inequalities:
I. A + B means A > B
II. A – B means A ≤ B
III. A × B means A ≥ B
IV. A ÷ B means A < B
V. A ± B means A = B
Now, translate the given statement:
- P × Q means P ≥ Q
- P – T means P ≤ T
- T ÷ R means T T ≥ P ≥ Q.
Now, let's evaluate the conclusions:
Conclusion 1: Q ± T means Q = T. From the combined inequality, T ≥ P ≥ Q. This implies T can be equal to Q, or T can be greater than Q. We cannot definitively conclude Q = T. So, Conclusion 1 does not follow.
Conclusion 2: S + Q means S > Q. From the combined inequality, S = R > T ≥ P ≥ Q. Since S is equal to R, and R is strictly greater than T, and T is greater than or equal to P, and P is greater than or equal to Q, it logically follows that S is strictly greater than Q. So, Conclusion 2 follows.
Therefore, only Conclusion 2 follows from the statement. This question tests logical reasoning, specifically decoding symbols and deriving conclusions from a chain of inequalities, a common topic in CSAT.

Question 61Permanent link
Which one of the following statements best reflects the most logical and rational massage conveyed by the author of the passage?
  1. A. Food yielding trees should replace other trees in rural and tribal areas and community owned lands.
  2. B. Food security cannot be ensured in India with the present practice of conventional agriculture.
  3. C. Wastelands and degraded areas in India should be converted into agroforestry systems to help the poor.
  4. D. Agroecosystems should be developed in addition to or along with conventional agriculture.
Show answer and explanation

Answer: D

Explanation

The passage advocates for a 'systemic approach to food consumption' by sourcing food from 'non-agricultural lands... in addition to agricultural lands.' It highlights how this diversification helps rural and tribal communities, provides a 'safety net during periods of food shortages caused by crop failure,' and fills 'seasonal crop production gaps.' The core message is about complementing conventional agriculture with other food sources. Option (D) 'Agroecosystems should be developed in addition to or along with conventional agriculture' perfectly captures this idea of integration and diversification for enhanced food security. Option (A) suggests replacement, which contradicts 'in addition to.' Option (B) makes a strong, negative claim about conventional agriculture that is not fully supported. Option (C) introduces 'wastelands and degraded areas' and 'agroforestry systems,' which are specific solutions not broadly discussed as the main message. This question tests the ability to identify the central recommendation or argument of the passage, a key skill for CSAT.

Question 62Permanent link
Which one of the following statements best reflects the most logical and practical message conveyed by the passage?
  1. A. It is necessary to put proper effluent treatment protocols in place.
  2. B. It is necessary to promote environmental awareness among people.
  3. C. Spread of drug-resistant bacteria cannot be done away with, as it is inherent in modern medical care.
  4. D. Pharma-manufacturing companies should be set up in remote rural areas, away from crowded towns and cities.
Show answer and explanation

Answer: A

Explanation

The passage explicitly identifies the lack of waste treatment by antibiotics-manufacturing companies as a significant environmental issue leading to drug-resistant infections. Therefore, the most direct, logical, and practical message conveyed is the imperative to implement proper effluent treatment protocols to address this specific source of pollution. Option (B) is too general and doesn't target the specific problem highlighted. Option (C) presents a pessimistic view not supported by the passage, which implies a solvable problem. Option (D) suggests relocation, which is a less direct and practical solution compared to treating waste at the source, as implied by the passage's focus on untreated waste.

Question 63Permanent link
Which one of the following statements best reflects the crux of the passage?
  1. A. To become a global power, India needs to invest in universal quality education.
  2. B. India is unable to become a global power because it is not focusing or promoting knowledge economy.
  3. C. Our education system should focus more on imparting skills during higher education.
  4. D. Parents of many school children are illiterate and are unaware of the benefits of quality education.
Show answer and explanation

Answer: A

Explanation

The passage strongly emphasizes that good quality school education and strong foundational skills are essential for individuals to acquire advanced skills and for a nation to compete in the global knowledge economy. It links an uneducated workforce to an inability to keep pace globally. Option (A) encapsulates this core message by stating that investment in universal quality education is crucial for national progress and global competitiveness. Option (B) makes a specific claim about India not directly supported. Option (C) contradicts the passage's focus on foundational skills at the primary level. Option (D) introduces an external factor not discussed in the passage.

Question 64Permanent link
40 children are standing in a circle and one of them (say child-1) has a ring. The ring is passed clockwise. Child-1passes on the child-2, child-2 passes on to child-4, child-4 passes on to child- 7 and so on. After how many such changes (including child-1) will the ring be in the hands of child-1 again?
  1. A. 14
  2. B. 15
  3. C. 16
  4. D. 17
Show answer and explanation

Answer: B

Explanation

The ring is passed with increasing increments: +1, +2, +3, +4, and so on. We need to find the number of passes (changes) until the ring returns to Child-1. Let C_n be the child holding the ring after 'n-1' passes (C_1 is the starting child). The position of the child is calculated modulo 40. The sequence of children holding the ring is: 1, 2 (1+1), 4 (2+2), 7 (4+3), 11 (7+4), 16 (11+5), 22 (16+6), 29 (22+7), 37 (29+8), 6 (37+9 = 46 mod 40), 16 (6+10), 27 (16+11), 39 (27+12), 12 (39+13 = 52 mod 40), 26 (12+14), 1 (26+15 = 41 mod 40). The ring returns to Child-1 after 15 passes. The question asks for 'how many such changes (including child-1)', which refers to the number of passes made to return to child-1, which is 15.

Question 65Permanent link
What is the middle terms of the sequence Z, Z, Y, Y, Y, X, X, X, X, W, W, W, W, W,…….,A?
  1. A. H
  2. B. I
  3. C. J
  4. D. M
Show answer and explanation

Answer: B

Explanation

The sequence consists of letters of the alphabet, where each letter appears a number of times equal to (28 - its position in the alphabet from A). So, Z (26th letter) appears 2 times, Y (25th) appears 3 times, ..., A (1st) appears 27 times. The total number of terms in the sequence is the sum 2 + 3 + 4 + ... + 27. This is an arithmetic series sum: (number of terms / 2) * (first term + last term) = (26/2) * (2 + 27) = 13 * 29 = 377. The middle term is (377 + 1) / 2 = 189th term. To find the 189th term, we sum the occurrences from Z downwards: Z (2), Y (3), X (4), W (5), V (6), U (7), T (8), S (9), R (10), Q (11), P (12), O (13), N (14), M (15), L (16), K (17), J (18), I (19). Summing these: 2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18 = 170. The next letter is 'I', which appears 19 times. The 189th term falls within the 'I' block (171st to 189th term). Thus, the middle term is I.

Question 66Permanent link
Questions: Is p greater than q? Statement-1: p × q is greater than zero. Statement-2: p^2 is greater than q^2.
  1. A. The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone.
  2. B. The Question can be answered by using either Statement alone.
  3. C. The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone.
  4. D. The Question cannot be answered even by using both the Statements together.
Show answer and explanation

Answer: D

Explanation

The question asks if p > q.
Statement 1: p × q > 0. This implies p and q have the same sign (both positive or both negative). If p=3, q=2, then p>q. If p=-2, q=-3, then p>q. But if p=2, q=3, then p<q. If p=-3, q=-2, then p q^2. This implies |p| > |q|. If p=3, q=2, then p>q. If p=-3, q=2, then pq. If p=-3, q=-2, then p |q|. If p and q are both positive, then p > q (e.g., p=3, q=2). If p and q are both negative, then p q. Therefore, the question cannot be answered even by using both statements together.

Question 67Permanent link
Questions: Is (p + q- r) greater than (p – q + r), where p, q and r are integers? Statement-1: (p - q) is positive. Statement-2: (p-r) is negative.
  1. A. The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone.
  2. B. The Question can be answered by using either Statement alone.
  3. C. The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone.
  4. D. The Question cannot be answered even by using both the Statements together.
Show answer and explanation

Answer: C

Explanation

The question asks: Is (p + q - r) > (p - q + r)?
Simplifying this inequality: p + q - r > p - q + r => 2q > 2r => q > r. So, the question is equivalent to asking: Is q > r?
Statement 1: (p - q) is positive, which means p > q. This statement gives no information about the relationship between q and r. Thus, Statement 1 alone is not sufficient.
Statement 2: (p - r) is negative, which means p q. From Statement 2, p < r. Together, these imply q < p < r. From this combined information, we can definitively conclude that q r?', and we found q < r, the answer is a definitive 'No'. Therefore, both statements together are necessary and sufficient to answer the question.

Question 68Permanent link
In a party, 75 persons took tea, 60 persons took coffee and 15 persons took both tea and coffee. No one taking milk takes tea. Each person takes at least one drink. Question: how many persons attended the party? Statement-1: 50 persons took milk. Statement-2: Number of persons who attended the party is five times the number of persons who took milk only.
  1. A. The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone.
  2. B. The Question can be answered by using either Statement alone.
  3. C. The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone.
  4. D. The Question cannot be answered even by using both the Statements together.
Show answer and explanation

Answer: A

Explanation

Let T be tea, C be coffee, M be milk. Given: |T|=75, |C|=60, |T∩C|=15. No one taking milk takes tea, so |M∩T|=0. Each person takes at least one drink.
Number of people taking only tea = 75 - 15 = 60.
Number of people taking only coffee = 60 - 15 = 45.
Number of people taking tea or coffee (or both) = 60 + 45 + 15 = 120.
Since |M∩T|=0, people taking milk either took only milk (M_only) or milk and coffee (M∩C). Total persons = 120 + M_only.
Statement 1: 50 persons took milk. This means M_only + M∩C = 50. We don't know M_only or M∩C individually, so we cannot find the total persons. Not sufficient.
Statement 2: Total persons = 5 × (M_only). We know Total persons = 120 + M_only. So, 120 + M_only = 5 × M_only => 120 = 4 × M_only => M_only = 30. Then, Total persons = 120 + 30 = 150. This statement alone is sufficient.
Therefore, the question can be answered by using Statement 2 alone, but not Statement 1 alone.

Question 69Permanent link
Consider a 3-digit number. Question: What is the number? Statement-1: The sum of the digits of the number is equal to the product of the digits. Statement-2: The number is divisible by the sum of the digits of the number.
  1. A. The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone.
  2. B. The Question can be answered by using either Statement alone.
  3. C. The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone.
  4. D. The Question cannot be answered even by using both the Statements together.
Show answer and explanation

Answer: D

Explanation

We need to find a unique 3-digit number.
Statement 1: Sum of digits = Product of digits. For example, if the digits are 1, 2, 3, then 1+2+3=6 and 1*2*3=6. Numbers like 123, 132, 213, 231, 312, 321 all satisfy this. Since there are multiple possibilities, Statement 1 alone is not sufficient.
Statement 2: The number is divisible by the sum of its digits. For example, 102 (sum=3, 102/3=34) and 108 (sum=9, 108/9=12) both satisfy this. Since there are multiple possibilities, Statement 2 alone is not sufficient.
Combining both statements: We look for numbers where the sum of digits equals the product of digits, AND the number is divisible by this sum. Using the example digits 1, 2, 3 (sum=6, product=6):
- 132: Sum=6, Product=6. 132 is divisible by 6 (132/6=22). This number satisfies both.
- 312: Sum=6, Product=6. 312 is divisible by 6 (312/6=52). This number also satisfies both.
Since both 132 and 312 satisfy both statements, we cannot determine a unique 3-digit number. Therefore, even using both statements together, the question cannot be answered.

Question 70Permanent link
For five children with ages a < b < c < d < e; any two successive ages differs by 2 years. Question: What is the age of the youngest child? Statement-1: The age of the eldest is 3 times the youngest. Statement-2: The average age of the children is 8 years
  1. A. The Question can be answered by using one of the Statement alone.
  2. B. The Question can be answered by using either Statement alone.
  3. C. The Question can be answered by using both the Statement together, but cannot be answered using either Statement alone.
  4. D. The Question cannot be answered even by using both the Statements together.
Show answer and explanation

Answer: B

Explanation

Let the age of the youngest child be 'a'. Since successive ages differ by 2 years, the ages of the five children are a, a+2, a+4, a+6, and a+8.
Statement 1: The age of the eldest is 3 times the youngest. So, a+8 = 3a. This simplifies to 2a = 8, which means a = 4. Since we found a unique value for 'a', Statement 1 alone is sufficient.
Statement 2: The average age of the children is 8 years. The sum of their ages is a + (a+2) + (a+4) + (a+6) + (a+8) = 5a + 20. The average is (5a + 20) / 5 = a + 4. Given that the average is 8, we have a + 4 = 8, which means a = 4. Since we found a unique value for 'a', Statement 2 alone is sufficient.
As either statement alone is sufficient to answer the question, option (B) is the correct choice.

Question 71Permanent link
With reference to the above passage, the following assumptions have been made: 1. Global warming is causing spring to come early and for longer durations. 2. Early spring and longer period of spring is not good for bird populations. Which of the above assumptions is/are correct?
  1. A. 1 only
  2. B. 2 only
  3. C. Both 1 and 2
  4. D. Neither 1 nor 2
Show answer and explanation

Answer: D

Explanation

Assumption 1: The passage states that 'warmer winters with less snow resulted in a longer lag time between spring events and a more protracted vernal window.' While this describes a change in spring timing, the passage does not explicitly attribute this phenomenon to 'global warming'. It presents an observation without stating its cause. Therefore, assuming global warming is the cause goes beyond the information provided.
Assumption 2: The passage mentions, 'As the ice melts earlier, the birds don't return, causing a delay, or lengthening in springtime ecological events.' This indicates a disruption in bird migration patterns. However, the passage does not explicitly state that this disruption is 'not good' for bird populations. It merely describes a change in ecological events without assigning a positive or negative value to it. Therefore, this assumption is also not directly supported by the passage. Since neither assumption can be definitively concluded from the passage, neither is correct.

Question 72Permanent link
Which one of the following statements best reflects the most logical, rational and crucial message implied by the passage?
  1. A. An enhanced efficiency of use of nitrogen is imperative for both food production and environment.
  2. B. Production of synthetic nitrogen fertilizers cannot be stopped as it will adversely affect global food security.
  3. C. Alternatives to crops that require excess of nitrogen should be identified and cultivated.
  4. D. Conventional agriculture using synthetic fertilizers should be replaced with agroforestry, agroecosystems and organic farming.
Show answer and explanation

Answer: A

Explanation

The passage highlights a critical dilemma: synthetic nitrogen fertilizers are essential for global food security, yet their inefficient use (60% lost to the environment) causes severe pollution. The core problem is the low 'nitrogen use efficiency'. Therefore, the most logical and crucial message is that improving this efficiency is vital to balance the needs of food production with environmental protection. Option (B) is a factual statement from the passage but not the overarching message. Options (C) and (D) propose specific solutions (alternative crops, replacing conventional agriculture) that go beyond the passage's primary focus on the problem of inefficient nitrogen use itself, which is the central theme.

Question 73Permanent link
Which one of the following statements best reflects the most logical, rational and crucial message conveyed by the passage?
  1. A. Climate justice should be ingrained in detail in the rules of all the new climate compacts/agreements.
  2. B. Environmental resources are unevenly distributed and exploited across the globe.
  3. C. There is an impending issue of dealing with a huge number of climate change victims/climate refugees.
  4. D. Climate changes in all its connotations is mostly due to developed countries and therefore their share of burden should be more.
Show answer and explanation

Answer: A

Explanation

The passage emphasizes the significance of climate justice, noting its lack of consensus in past climate compacts and highlighting that the 'crucial question' is how resources, technologies, and regulations will be used to support climate change victims, including adaptation and compensation. This strongly implies that for climate justice to be effectively addressed, it must be formally and thoroughly integrated into future climate agreements. Option (A) directly captures this need for formal inclusion and detailed rules. Option (B) is outside the scope of the passage. Option (C) describes a consequence but not the central message about the principle of climate justice itself. Option (D) introduces a specific attribution of responsibility, which, while related to climate justice, is not the primary message conveyed by the passage.

Question 74Permanent link
A principal P becomes Q in 1 year when compounded half-yearly with R% annual rate of interest. If the same principal P becomes Q in 1 year when compounded annually with S% annual rate of interest, then which one of the following is correct?
  1. A. R = S
  2. B. R > S
  3. C. R < S
  4. D. R ≤ S
Show answer and explanation

Answer: C

Explanation

For half-yearly compounding, the amount Q after 1 year is given by Q = P * (1 + (R/2)/100)^(1*2) = P * (1 + R/200)^2.
For annual compounding, the amount Q after 1 year is given by Q = P * (1 + S/100)^1.
Since the final amount Q is the same in both cases:
P * (1 + R/200)^2 = P * (1 + S/100)
(1 + R/200)^2 = 1 + S/100
Expanding the left side: 1 + 2*(R/200) + (R/200)^2 = 1 + S/100
1 + R/100 + R^2/40000 = 1 + S/100
Subtracting 1 from both sides and multiplying by 100:
R + R^2/400 = S
Since R is an annual rate of interest, R must be positive. Therefore, R^2/400 will be a positive value. This means S is equal to R plus a positive quantity. Hence, S > R, or R < S.

Question 75Permanent link
How many natural numbers are there which given a remainder of 31 when 1186 is divided by these natural numbers?
  1. A. 6
  2. B. 7
  3. C. 8
  4. D. 9
Show answer and explanation

Answer: D

Explanation

Let the natural number (divisor) be 'd'. According to the division algorithm, Dividend = Divisor × Quotient + Remainder. Here, 1186 = d × Q + 31. This implies d × Q = 1186 - 31 = 1155. A crucial condition for division is that the divisor 'd' must be greater than the remainder, so d > 31. We need to find the factors of 1155 that are greater than 31.
First, find the prime factorization of 1155: 1155 = 3 × 5 × 7 × 11.
Now, list all factors of 1155 and identify those greater than 31:
Factors: 1, 3, 5, 7, 11, 15 (3×5), 21 (3×7), 33 (3×11), 35 (5×7), 55 (5×11), 77 (7×11), 105 (3×5×7), 165 (3×5×11), 231 (3×7×11), 385 (5×7×11), 1155 (3×5×7×11).
Factors greater than 31 are: 33, 35, 55, 77, 105, 165, 231, 385, 1155. There are 9 such natural numbers.

Question 76Permanent link
Let pp, qq and rr be 2 digit numbers where p < q < r. If pp + qq + rr =tt0, where tt0 is a 3-digit number ending with zero, consider the following statements: 1. The number of possible values of p is 5. 2. The number of possible values of q is 6 Which of the above statements is/are correct?
  1. A. 1 only
  2. B. 2 only
  3. C. Both 1 and 2
  4. D. Neither 1 nor 2
Show answer and explanation

Answer: C

Explanation

The numbers pp, qq, rr can be written as 11p, 11q, 11r. So, 11p + 11q + 11r = 11(p+q+r) = tt0. Since tt0 is a 3-digit number ending with zero and a multiple of 11, it must be 110 or 220 (as max sum of p,q,r is 7+8+9=24, so 11*24=264; min sum is 1+2+3=6, so 11*6=66).
Case 1: p+q+r = 10 (if tt0=110). Given p<q<r, and p,q,r are digits 1-9.
Possible (p,q,r) triplets: (1,2,7), (1,3,6), (1,4,5), (2,3,5). Here, p can be 1 or 2 (2 values). q can be 2, 3, 4, 5 (3 distinct values: 2,3,4,5, but 5 is not possible for q as q<r, so q can be 2,3,4).
Case 2: p+q+r = 20 (if tt0=220). Given p<q<r.
Possible (p,q,r) triplets: (3,8,9), (4,7,9), (5,6,9), (5,7,8). Here, p can be 3, 4, or 5 (3 values). q can be 6, 7, 8, 9 (3 distinct values: 6,7,8,9, but 9 is not possible for q as q<r, so q can be 6,7,8).
Statement 1: Possible values for p are {1, 2} (from Case 1) and {3, 4, 5} (from Case 2). Total = 2+3 = 5 values. Statement 1 is correct.
Statement 2: Possible values for q are {2, 3, 4} (from Case 1) and {6, 7, 8} (from Case 2). Total = 3+3 = 6 values. Statement 2 is correct.
Both statements are correct.

Question 77Permanent link
What is the sum of all 4-digit numbers less than 2000 formed by the digits 1, 2, 3 and 4, where none of the digits is repeated?
  1. A. 7998
  2. B. 8028
  3. C. 8878
  4. D. 9238
Show answer and explanation

Answer: A

Explanation

To form 4-digit numbers less than 2000 using digits 1, 2, 3, and 4 without repetition, the thousands digit must be 1. The remaining three digits (2, 3, 4) can be arranged in the hundreds, tens, and units places in 3! (3 factorial) ways. 3! = 3 × 2 × 1 = 6 numbers.
The numbers are:
1234
1243
1324
1342
1423
1432
Summing these numbers:
Units place: 4+3+4+2+3+2 = 18 (write 8, carry 1)
Tens place: 3+4+2+4+2+3 + 1 (carry) = 19 (write 9, carry 1)
Hundreds place: 2+2+3+3+4+4 + 1 (carry) = 19 (write 9, carry 1)
Thousands place: 1+1+1+1+1+1 + 1 (carry) = 7 (write 7)
The total sum is 7998.

Question 78Permanent link
What is the number of selections of 10 consecutive things out of 12 things in a circle taken in the clockwise direction?
  1. A. 3
  2. B. 11
  3. C. 12
  4. D. 66
Show answer and explanation

Answer: C

Explanation

Consider the 12 things arranged in a circle, labeled 1 to 12 in a clockwise direction. We need to select 10 consecutive things. This means we are essentially choosing a starting point for our sequence of 10. If we start at thing 1, the selection is (1, 2, 3, 4, 5, 6, 7, 8, 9, 10). If we start at thing 2, the selection is (2, 3, 4, 5, 6, 7, 8, 9, 10, 11). This continues until we start at thing 12, which gives the selection (12, 1, 2, 3, 4, 5, 6, 7, 8, 9). Each of the 12 things can serve as the unique starting point for a sequence of 10 consecutive things. Therefore, there are 12 such selections.

Question 79Permanent link
If today is Sunday, then which day is it exactly on 10^10 th day?
  1. A. Wednesday
  2. B. Thursday
  3. C. Friday
  4. D. Saturday
Show answer and explanation

Answer: B

Explanation

To find the day on the 10^10th day from Sunday, we need to determine the remainder when 10^10 is divided by 7 (the number of days in a week). This remainder will tell us how many days after Sunday the target day falls.
First, find the remainder of 10 when divided by 7: 10 mod 7 = 3.
So, we need to calculate 3^10 mod 7.
Let's find the pattern of powers of 3 modulo 7:
3^1 ≡ 3 (mod 7)
3^2 ≡ 9 ≡ 2 (mod 7)
3^3 ≡ 3 × 2 ≡ 6 (mod 7)
3^4 ≡ 3 × 6 ≡ 18 ≡ 4 (mod 7)
3^5 ≡ 3 × 4 ≡ 12 ≡ 5 (mod 7)
3^6 ≡ 3 × 5 ≡ 15 ≡ 1 (mod 7)
The cycle length is 6. Now, divide the exponent 10 by 6: 10 = 1 × 6 + 4.
So, 3^10 ≡ (3^6)^1 × 3^4 ≡ 1^1 × 3^4 ≡ 3^4 ≡ 4 (mod 7).
The remainder is 4. Starting from Sunday, the 4th day after Sunday is Thursday (Sunday + 1 = Monday, +2 = Tuesday, +3 = Wednesday, +4 = Thursday).

Question 80Permanent link
There are three traffic signals. Each signal changes colour from green to red and then from red to green. The first signal takes 25 seconds, the second signal takes 39 seconds and the third signal takes 60 seconds to change the colour from green to red. The durations for green and red colours are same. At 2:00 p.m, they together turn green. At what time will they change to green next, simultaneously?
  1. A. 4:00 p.m.
  2. B. 4:10 p.m.
  3. C. 4:20 p.m.
  4. D. 4:30 p.m.
Show answer and explanation

Answer: B

Explanation

For each signal, the duration for green and red colors is the same. So, if a signal takes 'X' seconds to change from green to red, it also takes 'X' seconds to change from red to green. The total cycle time for each signal (from green to green) is 2X seconds.
Signal 1: Green to Red = 25s. Total cycle = 25s (Green) + 25s (Red) = 50 seconds.
Signal 2: Green to Red = 39s. Total cycle = 39s (Green) + 39s (Red) = 78 seconds.
Signal 3: Green to Red = 60s. Total cycle = 60s (Green) + 60s (Red) = 120 seconds.
They all turn green together at 2:00 p.m. To find when they will turn green together next, we need to find the Least Common Multiple (LCM) of their cycle times (50, 78, 120).
Prime factorization:
50 = 2 × 5^2
78 = 2 × 3 × 13
120 = 2^3 × 3 × 5
LCM(50, 78, 120) = 2^3 × 3 × 5^2 × 13 = 8 × 3 × 25 × 13 = 7800 seconds.
Convert 7800 seconds to minutes: 7800 / 60 = 130 minutes.
Convert 130 minutes to hours and minutes: 130 minutes = 2 hours and 10 minutes.
Since they turned green together at 2:00 p.m., they will turn green together next at 2:00 p.m. + 2 hours 10 minutes = 4:10 p.m.