Question 180690: 2. 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?
A. 2 hours and 24 minutes
B. 3 hours and 12 minutes
C. 3 hours and 44 minutes
D. 4 hours and 10 minutes
E. 4 hours and 33 minutes
Answer by Alan3354(69443)   (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?
A. 2 hours and 24 minutes
B. 3 hours and 12 minutes
C. 3 hours and 44 minutes
D. 4 hours and 10 minutes
E. 4 hours and 33 minutes
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Sally paints 1/4 of the house in an hour, John paints 1/6.
Together, they paint 1/4 + 1/6 per hour, = 5/12 of the house.
5/12 of the house per hour means they'll paint 1 house per 12/5 hours.
2.4 hours = 2 hrs 24 minutes.
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A quicker way to do these is product/sum: 4*6/(4+6) = 24/10 = 2.4
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