Question 712686
susie can rake all of the leaves on her lawn in 12 hours. lori takes 18hours to do the same job. how long does it take for them to rack the lawn together
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Susie rate: 1/12 job/hr
Lori rate:: 1/18 job/hr
Together rate: 1/x job/hr
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Equation:
rate + rate = together rate
1/12 + 1/18 = 1/x
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Multiply thru by 36x to get:
3x + 2x = 36
5x = 36
x = 7 1/5 hrs (time to do the job together)
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Cheers,
Stan H.