Working at their respective constant rates, machine A makes 100 copies in 8 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?	Answers:
A) 250
B) 425
C) 675
D) 825
E) 750
Machine A can produce 100 *30/8= 
<gadget id="calculator">100 *30/8</gadget>
<output>375</output>
375 copies   And, Machine B can produce 150* 30/10= 825 Copies   Total producing 700 Copies.   825 is the answer
<result>D</result>
Working at their respective constant rates, machine A makes 100 copies in 8 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?