UPSC Foundation 2026 and JPSC Mentorship admissions open Daily Current Affairs
learnpro Civil Services
LearnPro Menu
Home Current Affairs All Articles
UPSC
UPSC NOTES
STATE PSC
OPTIONAL SUBJECTS
CURRENT AFFAIRS
DAILY EDITORIAL
COURSES
DOWNLOAD NOTES
PYQ Papers Mains Answer Writing Online Courses

PYQ Question

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?

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

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.