SOLUTION: A new type of pump can drain a certain pool in 9 hours. An older pump can drain the pool in 11 hours. How long will it take both pumps working together to drain the pool?

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Question 1129103: A new type of pump can drain a certain pool in 9 hours. An older pump can drain the pool in 11 hours. How long will it take both pumps working together to drain the pool?
Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
1%2F9%2B1%2F11 pool per hours
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20%2F99


HOURS%2FPOOL:
99%2F20
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Answer by MathTherapy(10551) About Me  (Show Source):
You can put this solution on YOUR website!
A new type of pump can drain a certain pool in 9 hours. An older pump can drain the pool in 11 hours. How long will it take both pumps working together to drain the pool?
BE FOREWARNED!!

He's at it AGAIN!!! Yeah, the one with ARITHMETIC in his name. How IRONIC!! This is WRONG, so act as though no-one responded.

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HOURS%2FPOOL:



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