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 31054: 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 longjonsilver(2297) About Me  (Show Source):
You can put this solution on YOUR website!
so, Sally paints 1/4 of the house in an hour
and John paints 1/6 of the house in an hour.

Together, they paint +%281%2F4%29%2B%281%2F6%29+ in 1 hour.
--> +%283%2F12%29%2B%282%2F12%29+
--> +5%2F12+ in 1 hour

So, 5/12 of a house in 1 hour
5 houses in 12 hours
1 house in 12/5 hours

--> together they paint it in 2.4 hours which is 2 hours and 24 minutes.

jon.