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 poo working together?
Do not do any rounding.
Let x be the time it takes for the two hoses to fill the pool working together.
The rate at which the first hose fills the pool is 1 pool/85 minutes, and the rate at which the second hose fills the pool is 1 pool/40 minutes. Therefore, the combined rate at which the two hoses fill the pool is:
1/85 + 1/40 = 40/3400 + 85/3400 = 125/3400 pools/minute.
Since rate = work/time, we have:
125/3400 = 1/x
125x = 3400
x = 3400/125
x = 27.2
Therefore, it will take the two hoses 27.2 minutes to fill the pool working together.