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Pigeonhole principle (socks in the dark): Guarantee a matching pair with two colors available. Drawer contains 20 black socks and 20 brown socks. Socks are drawn in the dark (no color visibility). Minimum number of socks to guarantee at least one matching pair? Choose the correct value.

Q: Pigeonhole principle (socks in the dark): Guarantee a matching pair with two colors available. Drawer contains 20 black socks and 20 brown socks. Socks are drawn in the dark (no color visibility). Minimum number of socks to guarantee at least one m…

Concept With only two colors, the worst-case first two socks are different. The third sock must match one of them. Conclusion 3 socks guarantee a matching pair.

Difficulty: Easy

3
20
39
None of these

Correct Answer: 3

Explanation:

Concept
With only two colors, the worst-case first two socks are different. The third sock must match one of them.

Conclusion
3 socks guarantee a matching pair.

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