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China South East Mathematical Olympiad 2013 problem 8

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August 10, 2013
algebra unsolvedalgebra

Problem Statement

n3n\geq 3 is a integer. α,β,γ(0,1)\alpha,\beta,\gamma \in (0,1). For every ak,bk,ck0(k=1,2,,n)a_k,b_k,c_k\geq0(k=1,2,\dotsc,n) with k=1n(k+α)akα,k=1n(k+β)bkβ,k=1n(k+γ)ckγ\sum\limits_{k=1}^n(k+\alpha)a_k\leq \alpha, \sum\limits_{k=1}^n(k+\beta)b_k\leq \beta, \sum\limits_{k=1}^n(k+\gamma)c_k\leq \gamma, we always have k=1n(k+λ)akbkckλ\sum\limits_{k=1}^n(k+\lambda)a_kb_kc_k\leq \lambda. Find the minimum of λ\lambda