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Question 505173: If 10 men working 8 hours a day take 15 days to complete a job.How long will it take 20 men working 6 hours a day to complete the job?
B) If the two groups are combined how long will it take the new team to complete the same job if they work 10 hours a day?
Answer by lwsshak3(11628)   (Show Source):
You can put this solution on YOUR website! If 10 men working 8 hours a day take 15 days to complete a job.How long will it take 20 men working 6 hours a day to complete the job?
B) If the two groups are combined how long will it take the new team to complete the same job if they work 10 hours a day?
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first group takes 15 days to complete the job working 8 hrs/day
working 10 hrs/day, first group takes (8/10)*15=12 days to complete the job
Work rate of first group=1/12 working 10 hrs/day
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10/20*8/6*15=12 days second group takes to complete the job working 6 hrs/day
working 10 hrs/day, second group takes (6/10)*15=9 days to complete the job
Work rate of second group=1/9 working 10 hrs/day
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let x=days groups working together can complete the job
1/x = team work rate
sum of individual group work rates=work rate working together
1/12+1/9=1/x
x/12+x/9=1
LCD:36
4x+3x=36
7x=36
x=36/7
x=5-1/7 days
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