Question

Working together, two pumps can drain a certain pool in 4 hours. if it takes the older pump 12 hours to drain the pool by itself, how long will it take the newer pump to drain the pool on its own?

Do not do any rounding.

Answer 1

Let us assume the time taken by the newer
pump to drain the pool on its own = x
Time taken by the older pump to drain the pool on its own = 12 hours
Time taken by both pumps working together = 4 hours
Then
1/12 + 1/t = 1/4
1/t = 1/4 - 1/12
1/t = (3 - 1)/12
1/t = 2/12
1/t = 1/6
t = 6
From the above deduction, it can be concluded that the total time taken by the newer pump to drain the pool on its own is 6 hours. I hope the answer has come to your help.