Puzzle: There are three boxes, first box contains Apples, second box contains Oranges and the third box contains mix of both Apples and Oranges. Each box is wrongly labeled. You have got only once chance to open any box and pick up only one fruit without looking inside the box. The question is that which box would you choose to open and pick a single fruit so that you can tell what each box contains.
Answer: It is the boxed labeled with “Mixed Fruits”. The simple reason for this is when you pick up the box labeled with “Mixed Fruit”, either you could pick up Orange or Apple, and for sure this box would not have mixed fruits since the label must be wrong. So using these two facts we can conclude content of all the three boxes. If you happen to pick Apple, all the fruits must be apple in that box, and same thing for Orange, and the remaining two boxes must not contain what it is labeled, so the second box contains fruits labeled on third box and vice-versa.
I hope you liked the puzzle and the above answer is clear enough for you to understand.