Question 121271This question is from textbook college algebra
: A seweage treatment plant has two inlet pipes to its settling pond. One can fill the pond in 10hr, the other in 12hr If the first pipe is open for 5hrs and then the second pipe is opened, how long will it take to fill the pond.
This question is from textbook college algebra
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A sewage treatment plant has two inlet pipes to its settling pond. One can fill the pond in 10hr, the other in 12hr If the first pipe is open for 5hrs and then the second pipe is opened, how long will it take to fill the pond.
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1st Pipe DATA:
Time = 10 hr/job ; Rate = 1/10 job/hr
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2nd Pipe DATA:
Time = 12 hr/job ; Rate = 1/12 job/hr
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Let total number of hours to fill the pond be "x".
EQUATION:
5(1/10)+(x-5)(1/12) = 1 job
(1/2)+(1/12)x-(5/12)=1
(1/12)x = (1/2)+(5/12)
Multiply thru by 12 to get:
x = 6 + 5
x = 11 hrs (total # of hours to fill the pond)
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Cheers,
Stan H.
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