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Question 1093867: Carrie can inspect a case of watches in two hours. Jerry inspects a case in five hours. After inspecting a case for a half an hour, Carrie takes a break. In the mean time, Jerry takes over and completes the job, how long did this take him?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Carrie can inspect a case of watches in two hours. Jerry inspects a case in five hours. After inspecting a case for a half an hour, Carrie takes a break. In the mean time, Jerry takes over and completes the job, how long did this take him?
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Carrie rate = 1/2 case/hr
Jerry rate = 1/5 case/hr
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Note: rate*time = work done
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Carrie work + Jerry work = 1 job done
(1/2)(1/2) + x(1/5) = 1 job
1/4 + x/5 = 1
5 + 4x = 20
4x = 15
x = 15/4 hrs = 3 3/4 hrs = 3hr 45 minutes (Jerry's time)
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Cheers,
Stan H.
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