SOLUTION: It takes an older pump 3 times as long to drain a certain pool as it does a newer pump. Working together, it takes the two pumps 9 hours to drain the pool. How long will it take t

Question 1152252: It takes an older pump 3 times as long to drain a certain pool as it does a newer pump. Working together, it takes the two pumps 9 hours to drain the pool. How long will it take the older pump to drain the pool working alone?
Found 2 solutions by josgarithmetic, greenestamps:
Answer by josgarithmetic(39617) (Show Source): You can put this solution on YOUR website!
Rate for old pump
Rate for new pump
Rate for both pumps combined

-----------solve and find the value of .
Answer by greenestamps(13200) (Show Source): You can put this solution on YOUR website!

Since it takes the older pump 3 times as long as the newer pump to drain the pool, when working together the newer pump does 3/4 of the work and the older pump does 1/4.

Then, since the older pump drains 1/4 of the pool in those 9 hours when the pumps are both working, it will take the older pump 4*9 = 36 hours to drain the pool alone.

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