Working at their respective constant rates, machine A makes 100 copies in 20 minutes and machine B makes 150 copies in 10 minutes. If these machines work simultaneously at their respective rates for 30 minutes, what is the total number of copies that they will produce?	Pick
A) 250 B) 425 C) 675 D) 700 E) 600
Machine A can produce 100 *30/20= 
<gadget id="calculator">100 *30/20</gadget>
<output>150</output>
150 copies   And, Machine B can produce   150* 30/10= 
<gadget id="calculator">  150* 30/10</gadget>
<output>450</output>
450 Copies   Total producing 600 Copies.   600 is the answer
<result>E</result>
Working at their respective constant rates, machine A makes 100 copies in 20 minutes and machine B makes 150 copies in 10 minutes. If these machines work simultaneously at their respective rates for 30 minutes, what is the total number of copies that they will produce?