<PRE><B>Question 973655</B>
One highway worker can pick up all the trash on a strip of highway in 5 hours, and his helper can pick up the trash in 7 hours. How long will it take them if they work together?
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1st worker rate:: 1/5 job/hr
2nd worker rate:: 1/7 job/hr
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Together rate: 1/x job/hr
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Equation::
rate + rate = together rate
1/5 + 1/7 = 1/x
7x + 5x = 5*7
12x = 35
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x = 35/12 = 2 11/12 hrs = 2hr 55 minutes (time to do the job together)
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Cheers,
Stan H.
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