Five machines at a certain factory operate at the same constant rate. If four of these machines, operating simultaneously, take 20 hours to fill a certain production order, how many fewer hours does it take all five machines, operating simultaneously, to fill the same production order? Pick one.
A) 4
B) 5
C) 6
D) 16
E) 24
Total work = 4*20 machine hrs   Time taken = 4* 20 /5= 
<gadget id="calculator">4* 20 /5</gadget>
<output>16</output>
&gt; 16 hours...   Thus all five machines, operating simultaneously will take ( 20 - 16 ) 4 hours..   4nswer will be (4) 4
<result>A</result>
Five machines at a certain factory operate at the same constant rate. If four of these machines, operating simultaneously, take 20 hours to fill a certain production order, how many fewer hours does it take all five machines, operating simultaneously, to fill the same production order?