Socks in the dark
A drawer holds 10 black socks and 10 white socks. The room is dark.
- How many socks must you take to be sure of a matching pair?
- How many to be sure of a black pair?
Show hint
Think about the worst possible luck. This is the pigeonhole principle.
Show solution
- 3. With only two colours, three socks cannot all be different.
- 12. In the worst case the first 10 are all white, and you then need 2 black ones.
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