Problema Solution
It takes David 15hr. to put a roof on a house. It takes Loren 12hr. to put a roof on the same type of house. How long would it take to complete the job if they work together?
Answer provided by our tutors
Let 'x' represent the number of hours needed to complete the job when David and Loren are working together.
In 1 hour David will put 1/15 of the roof.
In 1 hour Loren will put 1/12 of the roof.
In 1 hour David and Loren will put 1/x of the roof.
Now we can write:
1/15 + 1/12 = 1/x
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click here to see the equation solved for x
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x = 20/3 hr
x = 6 hr (2*60/3) min
x = 6 hr 40 min
If David and Loren work together they will complete the job in 6 hours and 40 minutes.