MathDB
five nonnegative real numbers with sum 1 around a circle

Source: Germany Federal - Bundeswettbewerb Mathematik 1990, round 2, p3

February 21, 2020
combinatorics

Problem Statement

Given any five nonnegative real numbers with the sum 11, show that they can be arranged around a circle in such a way that the five products of two consecutive numbers sum up to at most 1/51/5.