The Riddler
Problems from FiveThirtyEight, modelled and solved
2026
Selected problems from Oliver Roeder's *Riddler* column at FiveThirtyEight, set out cleanly and solved with a mix of paper-and-pencil reasoning, generating-function techniques, and small Python simulations where the closed form is out of reach.
A working draft. The full collection covers the Express and Classic problems posed weekly between 2015 and 2024, with each entry following the same arc: problem statement, solution sketch, complete working, and where appropriate a short program that confirms the answer numerically.
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