+-1, at each of the 8 vertices of a given cube, product, sum
Source: Norwegian Mathematical Olympiad 1993 - Abel Competition p4
February 11, 2020
cubecombinatoricscombinatorial geometrySumProduct
Problem Statement
Each of the vertices of a given cube is given a value or .
Each of the faces is given the value of product of its four vertices.
Let be the sum of all the values. Which are the possible values of ?