Machine A produces 100 parts twice as fast as Machine B does. Machine B produces 100 parts in 80 minutes. If each machine produces parts at a constant rate, how many parts does Machine A produce in 20 minutes?  Choose the correct choice.
A) 60  B) 80  C) 70  D) 40  E) 50
Machine B produces 100 part in 80 minutes. Machine A produces 100 parts twice as fast as B, so Machine A produces 100 parts in  80/2= 
<gadget id="calculator"> 80/2</gadget>
<output>40</output>
40 minutes.   Now, Machine A produces 100 parts in 40 minutes which is 100/40= 10/4 parts/minute.   10/4 parts X a total of 20 minutes = 10/4 * 20= 
<gadget id="calculator">10/4 * 20</gadget>
<output>50</output>
50   50
<result>E</result>
Machine A produces 100 parts twice as fast as Machine B does. Machine B produces 100 parts in 80 minutes. If each machine produces parts at a constant rate, how many parts does Machine A produce in 20 minutes?