SOLUTION: It takes two hours for 4 boys to shovel a driveway. How many minutes does it take 5 boys to shovel the driveway?

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Question 759953: It takes two hours for 4 boys to shovel a driveway. How many minutes does it take 5 boys to shovel the driveway?
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
What is the work rate for 1 boy?

4 boys do the job in 2 hours;
1 boy does the job in 2*4 hours, or 8 hours.

* Rates of simultanous working boys are additive.
* Each boy works at the rate of 1/8 jobs per hour.
* Basic relationship is R%2At=j, using R for rate, t for time, j for how many jobs.

Five boys work together.
highlight%285%2A%281%2F8%29%2At=1%29
Find t hours.