MathDB
China Northern Mathematical Olympiad 2017, Problem 8

Source: China Northern Mathematical Olympiad 2017

July 29, 2017
inequalities

Problem Statement

Let n>1n>1 be an integer, and let x1,x2,...,xnx_1, x_2, ..., x_n be real numbers satisfying x1,x2,...,xn[0,n]x_1, x_2, ..., x_n \in [0,n] with x1x2...xn=(nx1)(nx2)...(nxn)x_1x_2...x_n = (n-x_1)(n-x_2)...(n-x_n). Find the maximum value of y=x1+x2+...+xny = x_1 + x_2 + ... + x_n.