If a copier makes 7 copies every 5 seconds, then he continues at this rate, how many minutes will it take to make 4200 copies?

Explanation

Let x be the time in seconds.The copier makes 7 copies every 5 seconds, so the rate is 7/5 copies per second.Now, set up the proportion:7/5=4200/xTo solve for x, cross-multiply:7x= 5 × 42007x= 21000Now, divide by 7 to find x:X = 21000/7= 3000So, it takes 3000 seconds to make 4200 copies.Now, let's convert 3000 seconds to minutes. There are 60 seconds in a minute:minutes=3000/60=50Therefore, it will take 50 minutes to make 4200 copies if the copier continues at this rate.