A Wolf, A Sheep And A Cabbage
Riddle: One day, a farmer goes to visit his friend Ovis orientalis aris to give a wolf, a sheep, and a cabbage. There's one problem: the lagoon is closed, and the only way he can cross is by the infamous Canis Lupus river. Fortunately, he has a boat. Unfortunately, he can only get one of the three things before collapsing and going to the ocean. To make matters worse, he has two big catches: if he leaves the wolf and the sheep, the wolf will eat the sheep, but if the sheep is alone with the cabbage, she will eat all of it. You know that you must give your friend all of the things you promised to give. What's the least number of moves to get across the river? Remember: You can only grab one thing, either the wolf, the sheep or the cabbage. Fortunately, when you finished one move, you can also go alone.
Answer: Start by the first step, where you can grab the wolf, sheep or cabbage. If you grab the wolf, the sheep will eat the cabbage, but that also means that you can't grab the cabbage, or there won't be any sheep. So the first choice is to grab the sheep. The second move is to go alone since it doesn't make any sense to go again with the cabbage. Now for the third, we can grab the wolf or the cabbage. For the sake of time, we'll focus on grabbing the wolf. But that means that at the fourth we need to get away the sheep, and for the fifth, we'll need to grab the cabbage. Otherwise, it will ''disappear''. For the sixth move, we don't need to do anything, and finally, we can across the sheep, for a minimum of 7 moves. If in the third move you have chosen the cabbage, you will have another ending, with the same number of moves: 7.
Source: https://www.riddles.com/9885
