SOLUTION: A pipe fills a tank in 8 hours. Another pipe empties the tank in 12 hours. If both pipes are opened together, how long will it take to fill the tank?

Question 644426: A pipe fills a tank in 8 hours. Another pipe empties the tank in 12 hours. If both pipes are opened together, how long will it take to fill the tank?
Answer by nerdybill(7384) (Show Source): You can put this solution on YOUR website!
A pipe fills a tank in 8 hours. Another pipe empties the tank in 12 hours. If both pipes are opened together, how long will it take to fill the tank?
.
Let x = time (hours) it takes for both
then
x(1/8 + 1/12) = 1
multiplying both sides by 24:
x(3 + 2) = 24
x(5) = 24
x = 24/5
x = 4.8 hours
or
x = 4 hours and 48 minutes
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