Question

A copy machine can print 780 copies every 4 minutes. A teacher printed 2,925 copies. How many minutes did it take?

Answer 1

15 minutes

Explanation:

Make the "print 780 copies every 4 minutes" into a conversion rate of pages/minute:

(780 copies)/(4 minutes) = 195 copies/minute

Find the time required to print 2,925 copies by dividing by the rate:

(2,925 copies)/(195 copies/minute)

The unit "copies" cancels and minutes moves to the top:

(2,925)/(195) minutes = 15 minutes