Question

A swimming pool holds 600,000 liters of water. The pool has two drainage pipes. When the pool is completely full, the first pipe alone can empty it in 150 minutes, and the second pipe alone can empty it in 100 minutes. When both pipes are draining together, how long does it take them to empty the pool?

Answer 1

Explanation:

Rate 1 1 pool / 150 min

Rate 2 1 pool / 100 min

Now add the rates together to drain 1 pool

1 pool / ( 1/150 + 1/100) = 60 min