# 65th BPSC Mains Answer Writing Day 21

## Day 21

### Statistics

Direction (1-5): Read the following information carefully and answer the given questions?There are 500 students in a school. Every student likes different color like red, yellow and blue. 36% of the students like Yellow and the ratio of the number of students like red and yellow only to the number of students like yellow and blue only is 2: 3. Number of students like all the colors is 20. Ratio of the number of students like only red to the number of students like only yellow is 3:2. Number of students like yellow only is equal to the number of students like yellow and blue only. Number of students like both red and blue is 50% of the number of students like only blue. The number of students like only Blue is equal to the number of students does not like any color.

1) Find the number of students does not like yellow?

2) What is the ratio of the number of students like at most two colors to the number of students like only red, only yellow and only blue together?

3) The number of students like Blue is approximately what percent of the number of students like red?

4) What is the difference between the number of students like two colors only and the number of students like at least two colors?

5) What is the sum of the number of students does not like any color and the number of students like all the three colors?

### General Science

1. Urban area flooding has been a frequent disaster in various cities of India.Briefly describe it and measures which needs to be taken to mitigate it with special reference to recent Patna flood in 2019.
2. Throw light on the water crisis in India?Write an account on the possible approaches for water conservation and management and steps taken by government.