This website contains problems from math contests. Problems and corresponding tags were obtained from the Art of Problem Solving website.

Tags were heavily modified to better represent problems.

AND:
OR:
NO:

Found problems: 1

2020 Switzerland Team Selection Test, 12
Tags: ininquility , algebra
Let $a,b,c,d$ be positive real numbers such that $a+b+c+d=1$ prove that: ($\frac{a^2}{a+b}+\frac{b^2}{b+c}+\frac{c^2}{c+d}+\frac{d^2}{d+a})^5 \geq 5^5(\frac{ac}{27})^2$