MathDB

A hundred and one coins in a circle

Source: 42nd International Tournament of Towns, Senior O-Level P5, Fall 2020

February 18, 2023

combinatoricsTournament of Towns

Problem Statement

There are 101 coins in a circle, each weights 10g or 11g. Prove that there exists a coin such that the total weight of the

k{}

coins to its left is equal to the total weight of the

k{}

coins to its right where a)

k = 50

and b)

k = 49

.
Alexandr Gribalko