<PRE><B>Question 808749</B>
Nine employees working at the same rate require 15 days to complete a task.
Find the no. of man-hrs required
9 * 15 = 135 man-hrs to do the job
:
 Which formula indicates how long it would take to do the same work if there were 3 additional employees each capable of working twice as fast as each of the original 9 employees? 
:
The 3 additional employees would be the same as 6 of the original employees
Let d = no. of days required by this group
9 + 6 = 15 men effectively
15d = 135
d = 135/15
d = 9 days with this group</PRE>