Problem A. 645. (May 2015)
A. 645. Do there exist infinitely many (not necessarily convex) 2015-gons in the plane such that every three of them have a common interior point, but no four have a common point?
Deadline expired on June 10, 2015.
2 students sent a solution. 1 point: 1 student. 0 point: 1 student.