SOLUTION: If Hose A can fill up a tank in 20 minutes and Hose B can fill up the tank in 15 minutes , how long will it take for the hose together to fill up the tank ?

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Question 446518: If Hose A can fill up a tank in 20 minutes and Hose B can fill up the tank in 15 minutes , how long will it take for the hose together to fill up the tank ?
Found 2 solutions by nerdybill, Alan3354:
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
If Hose A can fill up a tank in 20 minutes and Hose B can fill up the tank in 15 minutes , how long will it take for the hose together to fill up the tank ?
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Let x = time (minutes) it takes for both
then
x(1/20 + 1/15) = 1
multiplying both sides by 60:
x(3 + 4) = 60
7x = 60
x = 60/7
x = 8.57 minutes

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
If Hose A can fill up a tank in 20 minutes and Hose B can fill up the tank in 15 minutes , how long will it take for the hose together to fill up the tank ?
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Hose A fills 1/20 per minute.
Hose B fills 1/15 per minute.
Together, they fill 1/20 + 1/15 per minute = 35/300 per minute.
35/300 tanks per minute --? 300/35 minutes per tank.
300/35 = 60/7 minutes