Sixteen machines, each working at the same constant rate, together can complete a certain job in 12 days. How many additional machines, each working at the same constant rate, will be needed to complete the Job in 8 days?	Answers:	A) 2	B) 3	C) 4	D) 6	E) 8
Another solution which is faster is Since each machine works at a constant rate. The time needs to bought down from 12 to 8. So the new time is 2/3 of the original time. Thus to achieve this we need the rate to be 3/2 of original.   So 3/2* 16= 
<gadget id="calculator">3/2* 16</gadget>
<output>24</output>
24   So we need   24-16= 
<gadget id="calculator">  24-16</gadget>
<output>8</output>
8 more machines.   Answer : 8
<result>E</result>
Sixteen machines, each working at the same constant rate, together can complete a certain job in 12 days. How many additional machines, each working at the same constant rate, will be needed to complete the Job in 8 days?