<PRE><B>Question 393524</B>
Computer A can do a job in 4 hours. Computer B can do the same job in 2 hours. How long will it take them to complete the job working together?
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A rate = 1/4 job/hr
B rate = 1/2 job/hr
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Together rate: 1/x job/hr
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Equation:
rate + rate = together rate
1/4 + 1/2 = 1/x
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Multiply thru by 4x to get:
x + 2x = 4
3x = 4
x = 4/3 = 1hr and 20 min (time to do the job together)
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Cheers,
Stan H.
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