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MathNet 2011 Question 71

Math Olympiad Vault · MathNet 2011

Question 71

Let $a$, $b$, $c$ be positive real numbers. Prove that
$$
8(a+b+c)\left(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\right) \leq 9\left(1+\frac{a}{b}\right)\left(1+\frac{b}{c}\right)\left(1+\frac{c}{a}\right)
$$