SOLUTION: it costs $900 for the 10,000 mile service on a car. If the parts were $720 and the mechanic charged $90 per hour, how many hours did the service take?

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: it costs $900 for the 10,000 mile service on a car. If the parts were $720 and the mechanic charged $90 per hour, how many hours did the service take?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 1027400: it costs $900 for the 10,000 mile service on a car. If the parts were $720 and the mechanic charged $90 per hour, how many hours did the service take?
Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
Call the amount of hours he spent working, h.
Then we have as our setup
900 = 720 + 90h
Now subtract 720 from both sides and get
180 = 90h
Now divide by 90 and get
h = 2 hours