Question 701834
If 7 men can put up a fence in 8 hours, then 1 man can put up the fence in 7*8=56 hours.  Therefore, it takes 56 man-hours to put up the fence. 
Soooo, 6 men need 56/6=9 1/3 hours to put up the fence.  This means that they work 1 1/3 overtime hours

Hope this helps---ptaylor