A farmer has a goat, a wolf, and a cabbage. He wants to transport all three from one side of a river to the other. He has a boat, but it has only enough room for the farmer and one thing. The wolf willl eat the goat if they are left alone together, and the goat will eat the cabbage if they are left alone. How can the farmer get everything to the other side of the river.
Possible Solution:
1) Traveler + Goat cross
2) Traveler returns
3) Traveler + Wolf Cross
4) Traveler + Goat Return
5) Traveler + Cabbage Cross
6) Traveler Returns
7) Traveler + Goat Cross
-NewYorkTimes
The farmer can use the following steps to transport all three across the river safely:
1. The farmer takes the goat across the river and leaves it on the other side.
2. The farmer comes back alone to the original side.
3. The farmer then takes the wolf across the river and leaves it on the other side, but he brings the goat back with him to the original side.
4. The farmer leaves the goat on the original side, takes the cabbage across the river, and leaves it with the wolf on the other side.
5. Finally, the farmer comes back alone to the original side and takes the goat across the river.
This way, all three - the farmer, the wolf, the goat, and the cabbage - are safely transported to the other side without any of them being left alone together where one might eat another.
The solution is based on the idea that the farmer needs to ensure that at no point is either the goat left alone with the wolf or the cabbage left alone with the goat. By carefully managing the order and combination of what is transported, the farmer can safely transport all three items.