The average weight of 10 men is decreased by 2 kg when one of them whose weight is 60 kg is replaced by a new man. What is the weight of the new man?

40 Kg

Average weight of 10 men - x

1 man with 60kg weight was replaced by another man

Average weight of 10 man after replacement - x - 2

That means that the new man has weight less than 60kg which eventually resulted in an overall decrease in the average of all the men. 

So, weight of new woman can be calculated as: 

10 x 2 = 20 (Weight which he fell short of due to which the average reduced)

So, the weight of man is 60 - 20 = 40kg