The Three Vessels of the Sage belongs to the great tradition of problems that seem narrative and turn out to be exact. It preserves that ancient flavor in the statement, but requires a precise sequence that does not allow trial and error.
The three vessels of the wise man (ancient India)
Riddle statement
A wise man has three vessels of 12, 8 and 5 liters. The 12 is full; the other two are empty.
You must divide the content into two equal parts, using only transfers between vessels and without intermediate marks.
How do you do it?