Jan 28, 2016

Fox, Goose and Bag of Beans Puzzle

The fox, goose and bag of beans puzzle is a river crossing puzzle.

Once upon a time a farmer went to a market and purchased a fox, a goose, and a bag of beans. On his way home, the farmer came to the bank of a river and rented a boat. But in crossing the river by boat, the farmer could carry only himself and a single one of his purchases - the fox, the goose, or the bag of beans.

If left together, the fox would eat the goose, or the goose would eat the beans.

The farmer's challenge was to carry himself and his purchases to the far bank of the river, leaving each purchase intact. How did he do it?

If you can't figure it out you must not be a MPHS graduate.

Scroll down for the answer.

The first step must be to take the goose across the river, as any other will result in the goose or the beans being eaten. 

When the farmer returns to the original side, he has the choice of taking either the fox or the beans across next. If he takes the fox across, he would have to return to get the beans, resulting in the fox eating the goose. If he takes the beans across second, he will need to return to get the fox, resulting in the beans being eaten by the goose. 

The dilemma is solved by taking the fox (or the beans) over and bringing the goose back. Now he can take the beans (or the fox) over, and finally return to fetch the goose.

His actions in the solution are summarised in the following steps:
Take goose over
Take fox or beans over
Return with goose
Take beans or fox over
Take goose over

Thus there are seven crossings, four forward and three back.

And now you know the rest of the story.

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