SOLUTION: a tank is 3/4 full . Fill Pipe A can fill the tank in 12 minutes . Drainpipe B can empty it in 8 minutes . if both pipes are open , how long will it take to empty the tank ?

Question 878361: a tank is 3/4 full . Fill Pipe A can fill the tank in 12 minutes . Drainpipe B can empty it in 8 minutes . if both pipes are open , how long will it take to empty the tank ?
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
a tank is 3/4 full .
Fill Pipe A can fill the tank in 12 minutes .
Drainpipe B can empty it in 8 minutes .
if both pipes are open , how long will it take to empty the tank ?
:
let t = time to empty the tank with both pipes open
Let a full tank = 1, then 3/4 of a tank = .75
:
- = .75
multiply by 24, cancel the denominators
3t - 2t = 24(.75)
t = 18 minutes to empty the tank
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