MathDB
Minimum Perimeter of a Triangle

Source: 2003 China Second Round Olympiad

August 30, 2014
geometryperimeterfloor functioncalculusintegrationmodular arithmeticalgebra

Problem Statement

Let the three sides of a triangle be ,m,n\ell, m, n, respectively, satisfying >m>n\ell>m>n and {3104}={3m104}={3n104}\left\{\frac{3^\ell}{10^4}\right\}=\left\{\frac{3^m}{10^4}\right\}=\left\{\frac{3^n}{10^4}\right\}, where {x}=xx\{x\}=x-\lfloor{x}\rfloor and x\lfloor{x}\rfloor denotes the integral part of the number xx. Find the minimum perimeter of such a triangle.