The Birthday Problem
How many people must be in a room before two of them probably share a birthday? The answer is far smaller than you expect.
1939 (first published), circulating from the 1920s14 min read
Austrian applied mathematics and probability
Richard von Mises
1883 – 1953
Applied mathematician who worked on aerodynamics, plasticity and numerical analysis, and who built one of the twentieth century's two great foundations for probability — the frequentist theory of the "Kollektiv", the rival to Kolmogorov's axiomatic approach. Dismissed from Berlin in 1933, he taught in Istanbul and then at Harvard. His 1939 Istanbul paper on occupancy probabilities contains the first published treatment of the birthday problem.