Colors of points on a circle
Source: Vietnam TST 1997, Problem 6
July 28, 2008
combinatorics unsolvedcombinatorics
Problem Statement
Let , , be positive integers with 2 \le k \le \frac {n}{p \plus{} 1}. Let distinct points on a circle be given. These points are colored blue and red so that exactly points are blue and, on each arc determined by two consecutive blue points in clockwise direction, there are at least red points. How many such colorings are there?