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Opening Set

Fall 2026 · 8 problems

Don't just read it; fight it!

Paul Halmos

The set the club opened Fall 2026 with. Chosen to be inviting rather than hard: the McNugget numbers, a fair coin from a biased one, the two-envelopes paradox, ants on a stick, and the Josephus circle.

Download the problem set (PDF)

What is in it

Problems only — the club works these out together at meetings. Topic and attribution are listed as a starting point.

1. The Chicken McNugget Problem Number TheoryEasy
2. A Fair Coin from a Biased One Probability / Algorithms
3. Five Points in a Square Geometry / Pigeonhole
4. Coprime Neighbors Number Theory / Pigeonhole
5. The Two Envelopes Paradox Probability / Paradox
6. Ants on a Stick Combinatorics / Physical Reasoning
7. The Counterfeit Coin Logic / Information Theory
8. The Josephus Survivor Combinatorics / Recursion