MathDB
Translations [Combinatorial Geometry]

Source: Iranian National Math Olympiad (Final exam) 2006

September 14, 2006
geometrygeometric transformationvectortrigonometrydilationratioreal analysis

Problem Statement

Assume that CC is a convex subset of Rd\mathbb R^{d}. Suppose that C1,C2,,CnC_{1},C_{2},\dots,C_{n} are translations of CC that CiCC_{i}\cap C\neq\emptyset but CiCj=C_{i}\cap C_{j}=\emptyset. Prove that n3d1n\leq 3^{d}-1 Prove that 3d13^{d}-1 is the best bound. P.S. In the exam problem was given for n=3n=3.