SOLUTION: Construction A roofer requires 12 hours to shingle a roof. After the roofer and an apprentice work on a roof for 3 hours, the roofer moves on to another job. The apprentice requi

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Construction A roofer requires 12 hours to shingle a roof. After the roofer and an apprentice work on a roof for 3 hours, the roofer moves on to another job. The apprentice requi      Log On


   

Question 348900: Construction A roofer requires 12 hours to shingle a roof. After the
roofer and an apprentice work on a roof for 3 hours, the roofer moves
on to another job. The apprentice requires 12 more hours to finish the
job. How long would it take the apprentice, working alone, to do the job?
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
in the 3 hours that the roofer worked , he completed 1/4 of the job (3/12)

that means it takes the apprentice 15 hr (3+12) to do 3/4 of the job