Problem 5 of Fourth round - m-gons in an n-gon with a certain property
Source: I International Festival of Young Mathematicians Sozopol 2010, Theme for 10-12 grade
December 15, 2019
combinatoricspolygonPolygons
Problem Statement
Let be a convex -gon. What’s the number of -gons with vertices from such that between each two adjacent vertices of the -gon there are at least vertices from the -gon?