I once received the following question on an entance test into a computer course. It was the only question I couldn’t answer. After I was accepted, I asked for the answer, but forgot it only a few hours later. Does anyone else know the answer? The question went like this:

When two children want to share a piece of food, a common procedure is for one of them to divide it into two supposedly-equal portions, and the other can choose whichever he wants.

With this system, neither child can complain of recieving the smaller piece. The first one can’t complain, because he signed off on their being equal. And the second can’t complain, because he had the option of choosing whichever he thought was the larger.

The question: How can this logic be adapted to allow THREE children to divide something so that none can complain of unfairness?