User Tools

Site Tools


Problem of the Week

Problem 2 (due Monday, September 27)

a) Given three distinct parallel lines on the plane, prove that one can choose one point on each line so that the 3 points are vertices of an equilateral triangle.

b) Given four distinct parallel planes in the space, prove that one can choose one point on each plane so that the 4 points are vertices of a regular tetrahedron.


Every other Monday (starting 08/30/21), we will post a problem to engage our mathematical community in the problem solving activity and to enjoy mathematics outside of the classroom. Students (both undergraduate and graduate) are particularly encouraged to participate as there is no better way to practice math than working on challenging problems. If you have a solution and want to be a part of it, e-mail your solution to Marcin Mazur ( by the due date. We will post our solutions as well as novel solutions from the participants and record the names of those who've got the most number of solutions throughout each semester.

When you submit your solutions, please provide a detailed reasoning rather than just an answer. Also, please include some short info about yourself for our records.

Previous Problems and Solutions

  • Problem 1 Solutions submitted by Ashton Keith and Pluto Wang.
pow/start.txt · Last modified: 2021/09/14 00:25 by mazur