<PRE><B>Question 315536</B>
 Jack usually mows his lawn in 3 hours. Marilyn can mow the same yard in 5 hours. How much time would it take for them to mow the lawn together? 
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Jack DATA:
time = 3 hrs/job ; rate = 1/3 job/hr
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Marilyn DATA:
time = 5 hrs/job ; rate = 1/5 job/hr
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Together DATA:
time = x hrs/job ; rate = 1/x job/hr
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Equation:
rate + rate = together rate
1/3 + 1/5 = 1/x
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5x + 3x = 15
8x = 15
x = 15/8 = 1.875 hrs (time to do the job together)
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Cheers,
Stan H.</PRE>