Question 363816
  Working together, Paul and Daniel can pick forty bushels of apples in 4.95 hours.  Had he done it alone it would have taken Daniel 9 hours.  Find out how long it would take Paul to do it alone.
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The "trick" is to use the amount of work done per hour, the reciprocal of how many hours it takes.  Then you can add the terms.
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Paul & Daniel do 1/4.95 of the job per hour.
Daniel does 1/9 of the job per hour.
Paul takes x hours alone, so
Paul does 1/x of the job per hour.
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1/9 + 1/x = 1/4.95
Multiply thru by 9x
x + 9 = 9x/4.95 = x/0.55
x - x/0.55 = -9
x - 20x/11 = -9
-9x/11 = -9
x = 11 hours
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