SOLUTION: A and B take 8 hours to paint a house. If A did the job by himself it would take 12 hours. How long would it take B to paint the house on his own? I don't know where to start wi

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A and B take 8 hours to paint a house. If A did the job by himself it would take 12 hours. How long would it take B to paint the house on his own? I don't know where to start wi      Log On


   



Question 611033: A and B take 8 hours to paint a house. If A did the job by himself it would take 12 hours. How long would it take B to paint the house on his own?
I don't know where to start with this one as it must be shown as a linear equation.
Thank you for your help!

Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
A and B take 8 hours to paint a house. If A did the job by himself it would take 12 hours. How long would it take B to paint the house on his own?
.
Let x = time (hours) for B on his own
then
8(1/12 + 1/x) = 1
multiplying both sides by 12x:
8(x + 12) = 12x
8x + 96 = 12x
96 = 4x
28 hours = x