In a drawer, there are 10 black socks, 10 white socks, and 10 blue socks completely mixed up in the dark. What is the minimum number of socks you must pull out to guarantee you have at least one matching pair of any color?
4 socks
With 3 possible colors, by the Pigeonhole Principle, pulling 4 socks ensures that at least one color will appear twice, forming a matching pair.
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: Medium. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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