SOLUTION: marcy and justin work at the same rate, and together they can paint a house in nine days. they get ron, who also works at the same rate as marcy and justin, to help them paint the

Algebra ->  Rate-of-work-word-problems -> SOLUTION: marcy and justin work at the same rate, and together they can paint a house in nine days. they get ron, who also works at the same rate as marcy and justin, to help them paint the       Log On


   

Question 857612: marcy and justin work at the same rate, and together they can paint a house in nine days. they get ron, who also works at the same rate as marcy and justin, to help them paint the house. how long will it take the three of them to paint the house?
Answer by JulietG(1812) About Me  (Show Source):
You can put this solution on YOUR website!
Let's call a day an hour, just for clarity. Doesn't affect the equation.
M = J = R (same rate for all of them)
It takes 9 man-hours * 2 (technically, "man-days", but I don't know if that's a real term) to paint a house. 18 man-hours total.
When Ron joins them, it still takes 18 man-hours to paint the house, but now it's divided by three people. 18 / 3 = 6
Answer: 6 days