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Question 455412: The grass of a school field needs to be cut
Jack could mow it in 4 hours
James could mow it in 5 hours
Jerremy could mow it in 6 hours
John could mow it in 8 hours
How long would it take, if they all combined their efforts and worked at their individual rates, to cut all the grass?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! The grass of a school field needs to be cut
Jack could mow it in 4 hours
James could mow it in 5 hours
Jerremy could mow it in 6 hours
John could mow it in 8 hours
How long would it take, if they all combined their efforts and worked at their individual rates, to cut all the grass?
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Let the combined time be "x" hrs.
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Equation:
sum of individual rates = together rate
1/4 + 1/5 + 1/6 + 1/8 = 1/x
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Multiply thru by 120x to get:
30x + 24x + 15x = 120
69x = 120
x = 120/69 ~ 1 hr 44 minutes
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Cheers,
Stan H.
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