each lines of a set in a plane intersects exactly 15 other lines
Source: Czech-Polish-Slovak Junior Match 2016, team p3 CPSJ
January 20, 2020
combinatoricscombinatorial geometry
Problem Statement
On a plane several straight lines are drawn in such a way that each of them intersects exactly other lines. How many lines are drawn on the plane? Find all possibilities and justify your answer.Poland