If it takes 6 men 4 days to dig a hole 3 metres deep, how long will it take10 men to dig a hole 7 metres deep?
(6 w x 4 d ) / 3 m = 8 w-d/m w = workers d = day m = meters
8 w-d / m * 7 m / 10 w = 5.6 days
+36916 
