SOLUTION: A two year- old computer can be perform a certain job in 3hours if a new computer is allowed to assist the older computer, the job can be done in 1hour 20minutes how long would it
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Question 629005: A two year- old computer can be perform a certain job in 3hours if a new computer is allowed to assist the older computer, the job can be done in 1hour 20minutes how long would it take the new computer to perform the job on its own? Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! A two year- old computer can be perform a certain job in 3hours if a new computer is allowed to assist the older computer, the job can be done in 1hour 20minutes how long would it take the new computer to perform the job on its own?
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old comp. rate: 1/3 job/hr
together rate: 1/(7/6) = 6/7 job/hr
new comp. rate: 1/x job/hr
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Equation:
rate + rate = together rate
1/3 + 1/x = 6/7
Multiply thru by 21x to get:
6x + 21 = 18x
12x = 21
x = 7/4 hr = 1 hr 45 minutes (time for the new computer to do the job)
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Cheers,
Stan H.
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