Fair Distribution of Assets

A man is the owner of a winery who recently passed away. In his will, he left 21 barrels (seven of which are filled with wine, seven of which are half full, and seven of which are empty) to his three sons. However, the wine and barrels must be split, so that each son has the same number of full barrels, the same number of half-full barrels, and the same number of empty barrels. 

Note that there are no measuring devices handy. How can the barrels and wine be evenly divided?

This is how it can be done?

Source

Fairly Distributed Assets

What was dilemma? 

We have to make number of each barrel type divisible by 3.

1.Two half-full barrels are poured into 1 empty barrel. So we left with 8 full, 5 half-empty & 8 empty barrels.

2.Again transfer two half-fulled barrels into 1 empty. Now we have 9 full, 3 half-empty & 9 empty barrels.

Now it can be evenly divided as 3 full, 1 half-empty & 3 empty barrels (hence wine) among 3 sons.