SOLUTION: A new type of pump can drain a certain pool in 6 hours. An older pump can drain the pool in 14 hours. How long will it take both pumps working together to drain the pool ?
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-> SOLUTION: A new type of pump can drain a certain pool in 6 hours. An older pump can drain the pool in 14 hours. How long will it take both pumps working together to drain the pool ?
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Question 1140553: A new type of pump can drain a certain pool in 6 hours. An older pump can drain the pool in 14 hours. How long will it take both pumps working together to drain the pool ? Found 3 solutions by ikleyn, rothauserc, Alan3354:Answer by ikleyn(52776) (Show Source):
The new pump drains of the pool volume per hour.
The old pump drains of the pool volume per hour.
Working together, the two pumps drain = = of the pool volume per hour.
It means that the two pumps will drain the pool in hours = hours = 4.2 hours = 4 hours and 12 minutes. ANSWER
You can put this solution on YOUR website! let t be the hours it takes both pumps working together to drain the pool
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1/6 + (1/14) = (14 + 6)/84 = 20/84 = 10/42
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working together, the pumps do 10/42 of the job in 1 hour
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also working together they do 1/t per hour, then
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10/42 = 1/t
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invert the two fractions and solve for t
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t = 42/10
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t = 4.2
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working together, they empty the pool in 4.2 hours
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