A copy machine, working at a constant rate, makes 35 copies per minute. A second copy machine, working at a constant rate, makes 65 copies per minute. Working together at their respective rates, how many copies do the two machines make in half an hour ?  Choose the correct choice.
A) 3,000	B) 2,700	C) 4,500	D) 5,400	E) 324,000
Together the two machines make 35+65= 
<gadget id="calculator">35+65</gadget>
<output>100</output>
100 copies per minute. So, in half an hour they will make 100*30=3,000 copies.   3,000nswer: 3,000.
<result>A</result>
A copy machine, working at a constant rate, makes 35 copies per minute. A second copy machine, working at a constant rate, makes 65 copies per minute. Working together at their respective rates, how many copies do the two machines make in half an hour ?