SOLUTION: 40 men can complete a piece of work in 40 days.They started the work together. But at the end of each 10th day, 5 men left the job. The work would have been completed in how many d

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: 40 men can complete a piece of work in 40 days.They started the work together. But at the end of each 10th day, 5 men left the job. The work would have been completed in how many d      Log On


   

Question 1053831: 40 men can complete a piece of work in 40 days.They started the work together. But at the end of each 10th day, 5 men left the job. The work would have been completed in how many days ?
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
RT=J relates constant work rate, time, and quantity of jobs. Your example refers mostly to 1 job. If r is one-man work rate and there are n men working on the same job, the rate of this group is n%2Ar.

Look at how much of the job is done every 10 days...

Basic plan for work was 40%2Ar%2A40=1 from which r=1%2F1600.

Now check each ten-day increment of work done.
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40%281%2F1600%29%2A10
1%2F4
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35%281%2F1600%29%2A10
35%2F160
7%2F32
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30%281%2F1600%29%2A10
3%2F16
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25%281%2F1600%29%2A10
25%2F160
5%2F32
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What is the sum up to these end of 40 days?
8%2F32%2B7%2F32%2B6%2F32%2B5%2F32
26%2F32
Keep going...
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20%281%2F1600%29%2A10
1%2F8
-
15%281%2F1600%29%2A10
15%2F160
3%2F32
-
10%281%2F1600%29%2A10
1%2F16
-
5%281%2F1600%29%2A10
5%2F160
1%2F32
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What is the total sum of the job up to these 80 days?
26%2F32%2B1%2F8%2B3%2F32%2B1%2F16%2B1%2F32
32%2F32
highlight%2832%2F32=1%29
THIS IS ALL OF THE 80 DAYS.