Question

There are three boxes, one contains only apples, one contains only oranges, and one contains both apples and oranges. the boxes have been incorrectly labelled such that no label identifies the actual contents of the box it labels. opening just one box and without looking in the box, you take out one piece of fruit. by looking at the fruit, how can you immediately label all of the boxes correctly?

Answer 1

This is a difficult question to understand. Let me clear it out: 

There are three boxes, and all three are marked incorrectly. So let's assume:
Box 1: (labelled) Oranges
Box 2: Apples
Box 3: A+O (Apples + Oranges)

You have to pick a fruit from the box marked 'A+O' to verify.

If the fruit is Apple:
(i) The label would be either A+O or Apple.
(ii) As all the labels are incorrect, change it to 'Apple'
(iii) Change the 'Orange' one to A+O, and the 'Apple' one to Orange

If it is Orange, the same process, but vice-versa. 

Hope it helped, took half an hour trying to solve, verify if still in doubt.