<PRE><B>Question 138723</B>
It takes a child 3 times longer to vacuum a house than an adult.  If it takes one hour for 1 adult and 1 child working together to vacuum a house how long would it take each person working alone?
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Child DATA:
Time = 3x hrs/job ; Rate = 1/3x job/hr.

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Adult DATA:
Time = x hrs/job ; Rate = 1/x job/hr

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Together DATA:
Time = 1 hr/job Rate = 1 job/hr
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EQUATION:
rate + rate = together rate
1/3x + 1/x = 1
1 + 3 = 3x
3x = 4 hrs. (amount of time the child would require to do the job alone)
x = 4/3 hr. (amount of time the adult would require to do the job alone)
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Cheers,
Stan H.</PRE>