MathDB
Kosovo MO 2010 Grade 12, Problem 4

Source: Kosovo MO 2010 Grade 12, Problem 4

June 7, 2021
number theory

Problem Statement

Let (p1,p2,...,pn)(p_1,p_2,..., p_n) be a random permutation of the set {1,2,...,n)\{1,2,...,n). If nn is odd, prove that the product (p1−1)⋅(p2−2)⋅...⋅(pn−n)(p_1-1)\cdot (p_2-2)\cdot ...\cdot (p_n-n) is an even number. @below fixed.
Back to ProblemsView on AoPS