SOLUTION: A welder requires 24 h to do a job. After the welder and an apprentice work on the job for 12 h, the welder quits. The apprentice finishes the job in 16 h. How long would it take t
Algebra ->
Rate-of-work-word-problems
-> SOLUTION: A welder requires 24 h to do a job. After the welder and an apprentice work on the job for 12 h, the welder quits. The apprentice finishes the job in 16 h. How long would it take t
Log On
Question 922019: A welder requires 24 h to do a job. After the welder and an apprentice work on the job for 12 h, the welder quits. The apprentice finishes the job in 16 h. How long would it take the apprentice, working alone, to do the job? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! A welder requires 24 h to do a job.
After the welder and an apprentice work on the job for 12 h, the welder quits.
The apprentice finishes the job in 16 h.
How long would it take the apprentice, working alone, to do the job?
:
let a = time required by the apprentice to do the job alone
let the completed job = 1
:
From the information given we know the welder worked 12 hr and the apprentice worked: 12+16 = 28 hr
:
A shared work equation, each will do a fraction of the work, the two fractions add up to 1 + = 1
reduce the fraction + = 1
multiply equation by 2a, cancel the denominators and you have:
a + 2(28) = 2a
56 = 2a - a
a = 56 hrs for the apprentice to do the job alone
:
;
:
You can check this for yourself + = 1
