two pipes filling a swimming pool

Question

A pipe can fill a swimming pool in 8 hours. After it has been open for 3 hours a second pipe is opened and the pool is filled in another 2 hours. How long would it take the second pipe alone to fill the pool?

Answer 1

First pipe fills 5/8 of the pool.

Second pipe fills 3/8 in 2 hours.

It would need 5 1/3 hours working along.