Imagine that you have three boxes, one containing two black balls, one containing two white balls, and the third containing one black ball and one white ball.

The boxes were originally labelled for their contents (BB - WW - BW) but someone has inadvertently switched the labels so that now every box is incorrectly labelled.

Without looking inside, you are allowed to take one ball at a time out of any box that you wish, and by this process of sampling, you are to determine the contents of all three boxes.

What is the smallest number of drawings needed to do this?

I believe it would be 2. being that every box is incorrectly labeled no box contains the same contents. This is a given. Now then lets say out of the box that is Labeled BB you pull out two white balls. By doing this you know that the two black are in the BW box and the BW in the white box, because the balls must be in a different box from the original.

Posted by Lucifer on 2003-02-27 13:32:58