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Question 627308: A painter hires help for a job, if the painter works 4 times as fast as his assistant , how many hours will it take the both working together to paint a house that would of taken the Painter 20 hours to complete by himself?
Answer by htmentor(1343)   (Show Source):
You can put this solution on YOUR website! A painter hires help for a job, if the painter works 4 times as fast as his assistant , how many hours will it take the both working together to paint a house that would of taken the Painter 20 hours to complete by himself?
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The painter's work rate is 1 house per 20 hours = 1/20 house/hr
His assistant works at a rate of 1/4(1/20) = 1/80 house/hr
Working together, their combined rate is
1/20 + 1/80 = 4/80 + 1/80 = 5/80 house/hr
Taking the reciprocal gives 80/5 = 16 hr/house
So it takes 16 hrs working together
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