MathDB
max no of planes determined by these n lines

Source: 2021 Dürer Math Competition Regional E+5 https://artofproblemsolving.com/community/c2773609_2021_

January 7, 2022
combinatorial geometrycombinatoricslinesplanes3D geometrygeometry

Problem Statement

There are nn distinct lines in three-dimensional space such that no two lines are parallel and no three lines meet at one point. What is the maximal possible number of planes determined by these nn lines?
We say that a plane is determined if it contains at least two of the lines.