A boatman must carry a wolf, a goat and a cabbage across a river in a boat which is so small that he can carry at most, only one of them with him in at a time.Moreover whenever the wolf and goat are together, he must also be present to keep the goat from being eaten. Neither can he leave the alone with the cabbage, otherwise the goat will eat the cabbage. How can he carry all of them from the south bank of the river to the north bank?