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Mediterranean M.C. 2010 Problem 2

Source:

July 11, 2010
inequalitiesinequalities proposedMediterraneann-variable inequality

Problem Statement

Given the positive real numbers a1,a2,,an,a_{1},a_{2},\dots,a_{n}, such that n>2n>2 and a1+a2++an=1,a_{1}+a_{2}+\dots+a_{n}=1, prove that the inequality a2a3ana1+n2+a1a3ana2+n2++a1a2an1an+n21(n1)2 \frac{a_{2}\cdot a_{3}\cdot\dots\cdot a_{n}}{a_{1}+n-2}+\frac{a_{1}\cdot a_{3}\cdot\dots\cdot a_{n}}{a_{2}+n-2}+\dots+\frac{a_{1}\cdot a_{2}\cdot\dots\cdot a_{n-1}}{a_{n}+n-2}\leq\frac{1}{\left(n-1\right)^{2}}
does holds.