Answer:
28
Explanation:
number of copies done in 5 minute 15 seconds = 147
60 seconds is equal to 1 minute
1 second is equal to 1/60 minutes
therefore 15 seconds is equal to 1/60 * 15 minutes = 1/4 minutes
thus,
number of copies done in 5 1/4 minute = 147
number of copies done in 1 minute = 147/ 5 1/4 (as 147/21 = 7)
= 147/ (21/4) = 7*4 = 28
Thus, A copy machine makes 28 copies in 1 minute.