<PRE><B>Question 548504</B>
a window washer can wash the windows on one side of a building in 112 working hours.with an assistant he can do the job in 63 hours.how many hours would the assistant need to do the job alone
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washer rate = 1/112 job/hr
assist rate = 1/x job/hr
together rate = 1/63 job/hr
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Equation:
rate + rate = together rate
1/112 + 1/x = 1/63
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63x + 63*112 = 112x
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49x = 63*112
x = 144 hrs (time for the asst to do the job alone)
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Cheers,
Stan H.</PRE>