A box contains 10 red socks, 10 blue socks, and 10 green socks. What is the minimum number of socks you must blindly pull out to guarantee you have at least one matching pair of any color?
4 socks
By the Pigeonhole Principle, if you draw 4 socks and there are only 3 colors, at least one color must repeat, guaranteeing a matching pair.
About this riddle
Math riddles hide a calculation inside a short story. Pull out the numbers, work out what is being asked, and watch for a trick such as a unit change.
Difficulty: Medium. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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