SOLUTION: if it takes a pool 24 hours to fill with 4 pumps how many pumps will it take to fill the pool in 8 hours?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: if it takes a pool 24 hours to fill with 4 pumps how many pumps will it take to fill the pool in 8 hours?      Log On


   

Question 846135: if it takes a pool 24 hours to fill with 4 pumps how many pumps will it take to fill the pool in 8 hours?
Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
Are the pumps congruent? Find the rate for one pump. The rates of pumps operating at the same time are simply additive. This is a uniform rates problem so you want the rate of the pumping, based on the rate for one pump.

R*t=j ______________ and j for job, being "fill the pool".

4 pumps____________1%2F24 jobs per hour
1 pump_____________%281%2F%284%2A24%29%29=1%2F96 jobs per hour which is four times slower, which should intuitively make sense.

You have some unknown n pumps and you want t=8 hours.
highlight%28n%281%2F96%29%2A8=1%29;
Solve for n.