SOLUTION: It takes barry 4 hours to paint his house by himself when working alone. Christy can complete the job by herself in 11 hours. How long will it take them to complete the job if they

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: It takes barry 4 hours to paint his house by himself when working alone. Christy can complete the job by herself in 11 hours. How long will it take them to complete the job if they      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 874732: It takes barry 4 hours to paint his house by himself when working alone. Christy can complete the job by herself in 11 hours. How long will it take them to complete the job if they work together?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
It takes barry 4 hours to paint his house by himself when working alone.
Christy can complete the job by herself in 11 hours.
How long will it take them to complete the job if they work together?
:
let t = time to complete the job when working together
let the completed job = 1
:
Each will do a fraction of the job, the two fractions add up to 1
:
t%2F4 + t%2F11 = 1
multiply by 44. cancel the denominators and you have:
11t + 4t = 44
15d = 44
t = 44/15
t = 2.9333 hrs; 2 + .933(60) = 2 hr 56 min