Have a crack at it and see if you can figure it out. :-) (please try not to cheat either, it ruins the fun. ie; don't google it.)
<yath> There are three boxes. One has apples, one has oranges, and one has a mixture of apples and oranges.
<yath> You have the boxes. They were labeled correctly once, but someone has mixed up the labels and they are all mislabeled.
<yath> If you can take just one fruit from a box without looking into it, in order to correct the labels, which box should you take a fruit from and what will you do based on that information?