Question

One hose can fill a small swimming pool in 85 minutes. A larger hose can fill the pool in 40 minutes. How long will it take the two hoses to fill the pool working together?

Answer 1

Below

Explanation:

Rate1 = 1 pool / 85 min = 1/85

rate2 = 1 / 40

now find how long it will take with the combined rates

pool / (rates) = time

1 / ( 1/85 + 1/40) = 27.2 min