Question

One pump fills a swimming pool in 6hrs. A second pipe drains the pool in 9 hrs. If the pool starts empty, what part of the pool will be filled in each situation? Both pipes work for 3 hrs.

Please help fast!!

Answer 1

1/6

Explanation:

In 1 hour, the filling pump can fill 1:6 = 1/6 of the pool
In 1 hour, the draining pipe can drain 1:9 = 1/9 of the pool

So, in 1 hour, the pool is filled 1/6 - 1/9 = 1/18

By 3 hours, the pool would be filled 1/18 x 3 = 1/6.

So after 3 hours, the pool will be filled 1/6 of it.