MathDB
Random points in the unit circle

Source: IMC 2019 Day 2 P10

July 31, 2019
probabilitycollege contestsIMC

Problem Statement

20192019 points are chosen at random, independently, and distributed uniformly in the unit disc {(x,y)R2:x2+y21}\{(x,y)\in\mathbb R^2: x^2+y^2\le 1\}. Let CC be the convex hull of the chosen points. Which probability is larger: that CC is a polygon with three vertices, or a polygon with four vertices?
Proposed by Fedor Petrov, St. Petersburg State University