SOLUTION: If it takes Tap A 4 hours to fill an empty tank and Tap B 6 hours to drain the same tank when full, how long will it take for the tank to fill up when both taps are open?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: If it takes Tap A 4 hours to fill an empty tank and Tap B 6 hours to drain the same tank when full, how long will it take for the tank to fill up when both taps are open?      Log On


   



Question 997755: If it takes Tap A 4 hours to fill an empty tank and Tap B 6 hours to drain the same tank when full, how long will it take for the tank to fill up when both taps are open?
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
If it takes Tap A 4 hours to fill an empty tank and Tap B 6 hours to drain the same tank when full, how long will it take for the tank to fill up when both taps are open?
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Tap A adds 1/4 tank/hour
Tap B adds -1/6 tank/hour
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Together, 1/4 - 1/6 = 1/12 tank/hr
--> 12 hours/tank