SOLUTION: Helen and Dawn, working together, started a job that they could complete in 12 hours, but after 4 hours Helen had to leave. If Dawn could have done the job in 18 hours, how long wi

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Helen and Dawn, working together, started a job that they could complete in 12 hours, but after 4 hours Helen had to leave. If Dawn could have done the job in 18 hours, how long wi      Log On


   



Question 857595: Helen and Dawn, working together, started a job that they could complete in 12 hours, but after 4 hours Helen had to leave. If Dawn could have done the job in 18 hours, how long will it take her to finish it?
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
12/h+12/18=1
h = 36,
4/36+4/18+x/18=1,
1/9 +2/9+x/18=1
1/3+x/18=1
x/18=2/3
x=12
It would take Dawn 12 hours to hours to finish it.