30. Consider the following : 1. 1000 litres = 1m^3 2. 1 metric ton = 1000 kg 3. 1 hectare = 10000 m^2 Which of the 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

Answer: D

Explanation

Let’s evaluate each statement:
1. 1000 litres = 1 m^3: This is a correct standard conversion. One litre is defined as one cubic decimeter (1 dm^3). Since 1 meter = 10 decimeters, 1 cubic meter = (10 dm)^3 = 1000 dm^3 = 1000 litres. So, statement 1 is correct.
2. 1 metric ton = 1000 kg: This is the standard definition of a metric ton (also known as a tonne). So, statement 2 is correct.
3. 1 hectare = 10000 m^2: A hectare is a unit of area equal to 100 ares, and 1 are is 100 square meters. Therefore, 1 hectare = 100 × 100 m^2 = 10000 m^2. So, statement 3 is correct.
All three statements are correct standard units and conversions. This question tests general knowledge of common measurement units.