# Question #a8a49

##### 1 Answer

Apr 13, 2017

#### Answer:

I normally use a "strange" approach in this cases...anyway I got 1 hour and 45 minutes.

#### Explanation:

Let us call the quantity of water in the pool

meaning that the rate times the time will give us the amount of water pumped out.

Let us use the two pumps together; we get:

where

From the two previos equations we get:

that substituted into:

or: