SOLUTION: Jack usually mows his yard in 7 hours. Jane can mow the same yard in 3 hours. How much time will it take to mow it together?
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Question 442546: Jack usually mows his yard in 7 hours. Jane can mow the same yard in 3 hours. How much time will it take to mow it together?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Jack usually mows his yard in 7 hours. Jane can mow the same yard in 3 hours. How much time will it take to mow it together?
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Jack rate: 1/7 job/hr
Jane rate: 1/3 job/hr
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Together rate: 1/x job/hr
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Equation:
1/7 + 1/3 = 1/x
Multiply thru by 21x to get:
3x + 7x = 21
10x = 21
x = 2.1 hrs (time to do the job together)
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Cheers,
Stan H.
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