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Question 1050649: an experienced roofer can work twice as fast as helper. working together, they can shingle a new section of roof in 4 h. how long would it take the experienced roofer, working alone, to complete the same job
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! takes the experienced rooster x hours, the other 2x hours
in 1 hour, the experienced roofer does 1/x of the house, the inexperienced 1/2x hours
in 4 hours, the experienced does 4/x and the other 4/2x of the house.
That finishes it, so the two add to 1
(4/x)+(4/2x)=1
multiply everything by 2x
8+4=2x
2x=12
x=6 hours for the experienced one alone ANSWER
12 hours for the other
together (4/6)+(4/12)=1
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