MathDB
Serbia and Montenegro TST 2004

Source:

April 13, 2015
TSTinequalitiesSerbiathree variable inequality

Problem Statement

Let aa, bb and cc be real numbers such that abc=1abc=1. Prove that the most two of numbers 2a1b, 2b1c, 2c1a2a-\frac{1}{b},\ 2b-\frac{1}{c},\ 2c-\frac{1}{a} are greater than 11.