SOLUTION: It takes Rob 10 hours to clean an attic. Sam can clean the same attic in 11 hours. How long would it take them if they work together? Thank You!!

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Question 458867: It takes Rob 10 hours to clean an attic. Sam can clean the same attic in 11 hours. How long would it take them if they work together?
Thank You!!

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
It takes Rob 10 hours to clean an attic.
Sam can clean the same attic in 11 hours.
How long would it take them if they work together?
:
Let t = time if they work together
Let the completed job = 1 (a clean attic)
:
A typical shared work equation
:
t%2F10 + t%2F11 = 1
multiply by a common denominator, 110
110*t%2F10 + 110*t%2F11 = 110(1)
Cancel the denominators
11t + 10t = 110
:
21t = 110
t = 110%2F21
t = 5.238 hrs or about 5 hrs 14.3 min