SOLUTION: An inlet pipe on a swimming pool can be used to fill the pool in 18 hours. The drain pipe can be used to empty the pool in 20 hours. If the pool is 1/4 filled and then the inlet pi

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: An inlet pipe on a swimming pool can be used to fill the pool in 18 hours. The drain pipe can be used to empty the pool in 20 hours. If the pool is 1/4 filled and then the inlet pi      Log On


   

Question 956278: An inlet pipe on a swimming pool can be used to fill the pool in 18 hours. The drain pipe can be used to empty the pool in 20 hours. If the pool is 1/4 filled and then the inlet pipe and drain pipe are opened, how long from that time will it take to fill the pool? Help, setting up equation
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
Goal is to fill 3%2F4 of pool. The time is unknown.

RATES
Inlet, 1%2F18
Drain, -1%2F20

RT=V, rate time volume, where V will be how many pools.

%281%2F18-1%2F20%29t=3%2F4
Solve for t.