Five machines at a certain factory operate at the same constant rate. If four of these machines, operating simultaneously, take 25 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? Select:
A) 3
B) 5
C) 6
D) 16
E) 24
Total work = 4*25 machine hrs   Time taken = 4* 25 /5= 
<gadget id="calculator">4* 25 /5</gadget>
<output>20</output>
&gt; 20 hours...   Thus all five machines, operating simultaneously will take ( 25 - 20 ) 5 hours..   Answer will be (5) 5
<result>B</result>
Five machines at a certain factory operate at the same constant rate. If four of these machines, operating simultaneously, take 25 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?