Puzzle of the day

Question:

There are three boxes, each containing two balls. One box contains two white balls, another contains two black balls, and the third contains one white ball and one black ball. The boxes are labeled "White", "Black", and "Mixed", but all labels are incorrect. You can only draw one ball from one box to determine the correct labeling of all three boxes. Which box should you choose?

Answer:

Choose the "Mixed" box.

Explanation:

If you draw a white ball from the "Mixed" box, then the box must be the "White" box. If you draw a black ball, then the box must be the "Black" box. This leaves the remaining two boxes, which must be labeled incorrectly. Since the "White" box now has a black ball, it must be the "Black" box. Therefore, the "Black" box must be the "White" box, and the "Mixed" box must be the "Mixed" box.