Classic question: A farmer is crossing the river with a wolf, a sheep and a basket of cabbage. There is a boat by the river. Farmers can only take one of wolves, sheep and cabbage across the river at a time. When the farmer is away, the wolf will eat the sheep and the sheep will eat the cabbage. Ask farmers how to cross the river.

Answer:

1. The farmer led the sheep across the river and left them on the other side.

The farmer came back to cross the river with cabbage, threw the cabbage on the other side and brought the sheep back.

The farmer took the wolf across the river and left the wolf and cabbage on the other side.

The farmer came back to lead the sheep across the river. (completed)

Adaptation problem:

The family crossed the river. They are father, mother, two sons, two daughters, a servant and a dog. There is only one boat by the river, and the boat can only carry two of the above eight units at a time. Among them, only father, mother and servant can row a boat.

Make the following provisions (only provisions):

1. Father and son have contradictions, and even if mother is not around, there will be contradictions.

2. There are contradictions between mother and daughter, and there will be contradictions when father is not around.

3. Dogs have problems with others. Dogs bite when servants are not around.

Ask them how to cross the river safely.

Answer:

1, the servant led the dog across the river, left the dog on the other side and came back alone.

The servant took his daughter across the river, left her on the other side and brought the dog back.

Dad took another daughter across the river, left her on the other side and came back alone.

Father and mother crossed the river together, father stayed and mother came back alone.

The servant crossed the river with the dog and stayed on the other side. Dad came back alone.