SOLUTION: A towns old street sweeper can clean the streets in 60h. The old sweeper together with a new sweeper can clean the streets in 15h. How long would it take the new sweeper to do the

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A towns old street sweeper can clean the streets in 60h. The old sweeper together with a new sweeper can clean the streets in 15h. How long would it take the new sweeper to do the       Log On


   

Question 959398: A towns old street sweeper can clean the streets in 60h. The old sweeper together with a new sweeper can clean the streets in 15h. How long would it take the new sweeper to do the job alone?
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
1/60+1/X=1/15
1/X=1/15-1/60
1/X=4/60-1/60
1/X=3/60
3X=60
X=60/3
X=20 HOURS FOR THE NEW SWEEPER TO IT ALONE.
PROOF:
1/60+1/20=1/15
1/60+3/60=1/15
4/60=1/15 CROSS MULTIPLY.
60=60