SOLUTION: A contractor estimates that he could finish a project in 15 days if he has 20 men. At the start, he hired 10 men then after 6 days, 10 more men are added. How many days was the pro

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A contractor estimates that he could finish a project in 15 days if he has 20 men. At the start, he hired 10 men then after 6 days, 10 more men are added. How many days was the pro      Log On


   

Question 1055144: A contractor estimates that he could finish a project in 15 days if he has 20 men. At the start, he hired 10 men then after 6 days, 10 more men are added. How many days was the project delayed?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
1 project gets done in 15 days with 20 men
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Half as many men will take twice as long
to do 1 project, so
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1 project gets done in 30 days with 10 men
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In 1/5 of this time, only 1/5 of the project
will get done, so
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1/5 of the project gets done in 6 days with 10 men
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There is 4/5 of the project left, and 10 more
men are added untill the job is finished, so
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How many days will it take to do
4/5 of the project with 20 men?
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Since 1 project gets done in 15 days with 20 men,
4/5 of a project takes +%284%2F5%29%2A15+=+12+ days with 20 men
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The whole project gets done in +6+%2B+12+=+18+ days
The project was delayed 3 days since +18+-+15+=+3+
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If needed, get another opinion also