This is an old one but surprisingly, many peoples still don't know the answer. There is a river. On one end is a man, a wolf, a goat and a cabbage. There is a boat which has to be used to cross the river. However, the man can take only one thing with him at one time. Now if the goat and the cabbage is left behind, the goat will eat it and if the goat and wolf are left behind, the wolf will eat the goat.
How will he cross the river with the two animals and the cabbage?