Question 298198
Given,
 Three men can cut 72 trees in three hours
So the number of trees cut by one man in one hour = 72/(3*3) = 8
 Because of a shortage of space, each time one man is added, each of the workers can cut one less tree per hour.
When 5 men work together, the number of trees cut by one man 
in one hour = 8-2 = 6
So, the number of trees cut by 5 men in 5 hours = 6*5*5 = 150