SOLUTION: A carpenter can complete a job in 5 hours. After working on the job for 2 hours, an assistant helped finish the job. Together they completed the job in 1 hour. How long might it ta

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: A carpenter can complete a job in 5 hours. After working on the job for 2 hours, an assistant helped finish the job. Together they completed the job in 1 hour. How long might it ta      Log On


   

Question 725110: A carpenter can complete a job in 5 hours. After working on the job for 2 hours, an assistant helped finish the job. Together they completed the job in 1 hour. How long might it take the assistant , working alone, to complete a job similar to this one?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
A carpenter can complete a job in 5 hours.
After working on the job for 2 hours, an assistant helped finish the job.
Together they completed the job in 1 hour.
How long might it take the assistant, working alone, to complete a job similar to this one?
:
let a = time required by the assistant working alone
let the completed job = 1
:
The carpenter worked a total 3 hrs, the assistant for 1 hr,
a shared work equation
;
3%2F5 + 1%2Fa = 1
multiply by 5a, results:
3a + 5(1) = 5a
5 = 5a - 3a
5 = 2a
a = 5/2
a = 2.5 hrs
:
:
Check
3%2F5 + 1%2F2.5 = 1