Source: Nigerian Mathematics olympiad 2021 round 2 problem 4
February 15, 2021
algebrainequalitiesnumber theoryrelatively prime
Problem Statement
let x1, x2 .... x6 be non-negative reals such that x1+x2+x3+x4+x5+x6=1 and x1x3x5 + x2x4x6≥5401. Let p and q be relatively prime integers such that qp is the maximum value of x1x2x3+x2x3x4+x3x4x5+x4x5x6+x5x6x1+x6x1x2. Find p+q