SOLUTION: 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 wo

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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?
--------
Let the combined time be "x" hrs.
---
Equation:
sum of individual rates = together rate
1/4 + 1/5 + 1/6 + 1/8 = 1/x
-----------------------------------
Multiply thru by 120x to get:
30x + 24x + 15x = 120
69x = 120
x = 120/69 ~ 1 hr 44 minutes
=================================
Cheers,
Stan H.

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