A dark wardrobe holds 50 pairs of shoes, each pair consisting of one left shoe and one right shoe (100 individual shoes total). Without being able to see inside, what is the absolute minimum number of shoes you must pull out to guarantee you have at least one matching pair?
51 shoes
By the Pigeonhole Principle, the worst-case scenario involves drawing all 50 left shoes (or all 50 right shoes) consecutively without a match. The 51st shoe drawn must match one of the 50 opposite shoes already pulled.
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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