Eric Weisstein says the problem is solvable using trilinear coordinates.

Note that the problem he describes is somewhat more restrictive: either you have 3 jugs with certain amounts of liquid, or you have just 2 jugs and an infinite supply of liquid (so, no arbitrary large jug).

Here is some math describing the 3 jugs problem where all jugs have finite (integer) size, and no water is to be spilled (and no infinite supply available).