SOLUTION: Mike takes 8 hours to paint his room. After working for 1 hour, he called in a painter to help him. Working together, they finished the job in 3 more hours. How long the whole job

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Mike takes 8 hours to paint his room. After working for 1 hour, he called in a painter to help him. Working together, they finished the job in 3 more hours. How long the whole job       Log On


   

Question 533805: Mike takes 8 hours to paint his room. After working for 1 hour, he called in a painter to help him. Working together, they finished the job in 3 more hours. How long the whole job would be finished by the painter if he had worked alone?
Answer by J2R2R(94) About Me  (Show Source):
You can put this solution on YOUR website!
Every hour Mike works at a rate of 1/8 of the job.

After an hour he gets the painter in which increases the rate and so has 7/8 of the job left to do in the remaining three hours. This is equivalent to 7/24 per hour.

Mike we already know is 1/8 = 3/24
Mike and the painter do 7/24
Therefore the painter is 4/24 = 1/6
This means the painter would have done the job in 6 hours on his own.

Check:
First hour : 1/8
Remaining three hours: 3/8 + 3/6 = 7/8
1/8 + 7/8 = 1 Correct.