In a market, a farmer bought a wolf, a sheep, and a cabbage. The farmer stopped at a river's edge on his way home and rented a boat. However, the farmer could only get himself and one of his purchases across the river in a boat: either the wolf, the sheep, or the cabbage.

If left unattended together, the wolf would eat the sheep, or the sheep would eat the cabbage.

The farmer's task was to move himself and all of his purchases to the other side of the bank of the river while maintaining the integrity of each one.