If 70 men can work in 35 days, 40 men complete this work in days?

If 70 men can work in 35 days, 40 men complete this work in days?

Explanation

Find how many man-days to complete the road:

70*35 = 2450 man-days

Let d = days required for 40 men to do it.

40d = 2450

d=402450=61.25