SOLUTION: new copy machine takes 20 mins to copy exams old copy machine take 30 mins to copy exams how long does it take if both copy machines are used?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: new copy machine takes 20 mins to copy exams old copy machine take 30 mins to copy exams how long does it take if both copy machines are used?      Log On


   

Question 816422: new copy machine takes 20 mins to copy exams
old copy machine take 30 mins to copy exams
how long does it take if both copy machines are used?
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
x/20+x/30=1
3x/60+2x/60=1
5x/60=1
x/12=1
x=12 mins