IMO 2007 Shortlist A7

Let n > 1 be an integer. In the space, consider the set S =  (x,y,z) | x,y,z ∈ {0,1,...,n}, x + y + z > 0 . Find the sm...

IMO 2007 Shortlist A7

Category: Algebra

Problem

Let n > 1 be an integer. In the space, consider the set S =  (x,y,z) | x,y,z ∈ {0,1,...,n}, x + y + z > 0 . Find the smallest number of planes that jointly contain all (n+1)3 −1 points of S but none of them passes through the origin. (Netherlands)