MathDB
2009 Philippines MO P4

Source:

November 16, 2015
PMO2009algebraInequalityminimum value

Problem Statement

Let kk be a positive real number such that 1k+a+1k+b+1k+c1\frac{1}{k+a} + \frac{1}{k+b} + \frac{1}{k+c} \leq 1 for any positive positive real numbers aa, bb and cc with abc=1abc = 1. Find the minimum value of kk.