How long a small hose can fill a pool compared to a larger one

Question

Two hoses with different diameters can fill a swimming pool in 5 hours. If the larger hose alone fills it in 8 hours, how long would it take the smaller hose alone? Round to the nearest tenth.

Answer 1

Stevi, we look at how much is done per hour. In 1 hour, 1/5 of the tank is filled. The larger hose alone would fill 1/8, and the smaller 1/x, if x = the hours it would take.

 

1/8 + 1/x = 1/5

1/x = 1/5 - 1/8 = 8/40 - 5/40

1/x = 3/40

3x = 40

x = 13.3

 

Hope this helps!