2013 HMMT Guts #27: Intersection of Hypercube and Hyperplane
Source:
March 26, 2013
HMMT
Problem Statement
Let W be the hypercube {(x1,x2,x3,x4)∣0≤x1,x2,x3,x4≤1}. The intersection of W and a hyperplane parallel to x1+x2+x3+x4=0 is a non-degenerate 3-dimensional polyhedron. What is the maximum number of faces of this polyhedron?