A sock drawer contains 10 loose red socks and 10 loose blue socks. The room is pitch black and you cannot see the colors. What is the minimum number of socks you must pull out to be 100% certain you have at least one matching pair?
3 socks
There are only two possible colors (red and blue). By the Pigeonhole Principle, pulling 3 socks guarantees that at least two of them will share the same color.
About this riddle
Logic riddles give you a few facts and ask what must be true. List what you know, cross out what cannot be, and see what is left.
Difficulty: Easy. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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