One copy machine can make 25 copies a minute, and a second copy machine makes 35 copies a minute. If the two copiers work together, how long would it take them to make 4,800 copies? Choices:
A) 30 minutes
B) 40 minutes
C) 60 minutes
D) 70 minutes
E) 80 minutes
Total work done by both machines in a minute = 25 + 35= 
<gadget id="calculator">25 + 35</gadget>
<output>60</output>
60 copies   Total number of copies required= 6000   Time = 4800/60= 
<gadget id="calculator">4800/60</gadget>
<output>80</output>
80 mins   Answer 80 minutes
<result>E</result>
One copy machine can make 25 copies a minute, and a second copy machine makes 35 copies a minute. If the two copiers work together, how long would it take them to make 4,800 copies?