Three heirs inherited 21 barrels; of these barrels, 7 are half full, 7 are completely full of wine, and 7 are empty. How should they divide them so that without mixing or transferring the wine, each heir receives 7 barrels and an equal amount of wine?
The first gets 2 full, 3 half-filled, and 2 empty barrels, the second gets the same, and the third gets 3 full, 1 half-filled, and 3 empty barrels; or the first gets 1 full, 5 half-filled, and 1 empty barrel, and the second and third each get 3 full, 1 half-filled, and 3 empty barrels.

The number of solutions is 47.