There are three closed boxes labeled 'apples', 'pears', and 'apples and pears'. All three labels are wrong. How many fruits must be taken from one chosen box to determine all the contents?
Show hints
- Start with the box labeled 'apples and pears'.
- Because all 3 labels are wrong, seeing 1 fruit is enough.
Show the answer and solution
Answer: 1
It is enough to take 1 fruit from the box labeled 'apples and pears'. That label is wrong, so it contains one kind. After seeing it, the other two boxes follow from their wrong labels.