0, 1, 2, ..., 9 are written in some order on the circumference
Source: 1999 Estonia National Olympiad Final Round grade 12 p5
March 11, 2020
circlenumbersconsecutiveSumnumber theorycombinatorics
Problem Statement
The numbers are written (in some order) on the circumference. Prove that
a) there are three consecutive numbers with the sum being at least ,
b) it is not necessarily the case that there exist three consecutive numbers with the sum more than .