Answer:
The copy machine makes 32 copies per minute.
Explanation:
Given that a copy machine makes 136 copies in 4 minutes and 15 seconds, to determine how many copies does it make per minute, the following calculation must be performed: 
 
15 seconds = 0.25 minutes 
136 / 4.25 = X 
32 = X 
 
Therefore, the copy machine makes 32 copies per minute.