SOLUTION: A pipe can fill a tank in 30 minutes. A second pipe can fill the same tank in 20 minutes. A drain can empty the tank in 15 minutes. If you left the drain open, how long will it t

Question 915624: A pipe can fill a tank in 30 minutes. A second pipe can fill the same tank in 20 minutes. A drain can empty the tank in 15 minutes. If you left the drain open, how long will it take to fill the tank with both pipes open?
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Add the rates of filling and subtract
the rate of draining

Multiply both sides by

It will take 1 hour with both filling pipes
open and the drain open
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