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Question 136969: can you solve?
It takes one man 10 hours to do a certain job. After he has been at work for 4 hours, another man is sent to help. The two men complete the job in 2 more hours. How long would it have taken the second man to do the job alone?
I am more interested in the work then the answer so please show me step by step
thanks for the help
Answer by scott8148(6628)   (Show Source):
You can put this solution on YOUR website! the first man takes 10 hr to do the job; he works for 6 hrs (4+2), so he does 6/10 of the job
the second man does 4/10 (1-6/10) of the job in 2 hrs, so it would take him 5 hrs (2/(4/10)) to do the job alone
the fraction of the job done by each man is his time spent working divided by his time to do the job alone
__ the fractions add to 1, the whole job
let x="second man alone" __ 6/10+2/x=1 __ multiplying by 10x __ 6x+20=10x __ 20=4x
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