Inequality for geometric and arithmetic mean for n-1 numbers
Source: IMO ShortList 1991, Problem 26 (CZE 1)
August 15, 2008
Inequalityalgebrapolynomialn-variable inequalityIMO Shortlist
Problem Statement
Let and let satisfying i \equal{} 1, \ldots, n, and \sum^n_{i\equal{}1} a_i \equal{} \sum^n_{i\equal{}1} b_i. Prove the inequality: \sum^n_{i\equal{}1} b_i \prod^n_{j \equal{} 1, j \neq i} a_j \leq \frac{p}{(n\minus{}1)^{n\minus{}1}}.