SOLUTION: If Sally can paint a house in 4 hours, and John can paint the same house in 6 hour, how long will it take for both of them to paint the house together?

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Question 80456: If Sally can paint a house in 4 hours, and John can paint the same house in 6 hour, how long will it take for both of them to paint the house together?


Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
If Sally can paint a house in 4 hours, and John can paint the same house in 6 hour, how long will it take for both of them to paint the house together?
:
Let t = time required to complete the job together
:
Let the completed job = 1
:
A simple equation:
t%2F4 + t%2F6 = 1
:
Multiply equation by 12 to get rid of the denominators, you then have:
3t + 2t = 12
:
5t = 12
:
t = 12/5
:
t = 2.4 hrs working together
:
:
Check solution of t = 2.4:
2.4/4 + 2.4/6 =
.6 + .4 = 1