SOLUTION: A roofer requires 12 h to shingle a roof. After the roofer and an apprentice work on a roof for 9 h, the roofer moves on to another job. The apprentice requires 8 more hours to fin

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A roofer requires 12 h to shingle a roof. After the roofer and an apprentice work on a roof for 9 h, the roofer moves on to another job. The apprentice requires 8 more hours to fin      Log On


   

Question 733516: A roofer requires 12 h to shingle a roof. After the roofer and an apprentice work on a roof for 9 h, the roofer moves on to another job. The apprentice requires 8 more hours to finish the job. How long would it take the apprentice, working alone, to do the job?
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
9/12+9/h+8/h=1
17/h=1/4
4*17=h
68=h
The roofer did 9/12(3/4) of the job
which means the apprentice had to do 1/4 of the job.
it took him 17 hours to do 1/4 of the job
Damn he is slow