A person X can complete 20% of work in 8 days

A person X can complete 20% of work in 8 days and another person Y can complete 25% of the same work in 6 days. If they work together, in how many days will 40% of the work by completed?

1. 6
2. 8
3. 10
4. 12

• Answer: The correct option is A
• Explanation:

  X can complete 20% of work in 8 days. So, he will complete 100% work in 40 days.

  Similarly, Y can complete 25% of work in 6 days. So, he will complete 100% work in 24 days.

  In 1 day, the amount of work they will complete while working together = 1/40 + 1/24

  = (3 + 5)/120 = 8/120 = 1/15

  So, they need 15 days to complete the whole work.

  Time needed to complete 40% of the work = 40% of 15 = 6 days.

• Exam Year: 2020