MathDB
12 rectangular parallelepipeds with edges parallel to axes

Source: ARO 2005 - problem 11.6

April 30, 2005
analytic geometrypigeonhole principlegeometry unsolvedgeometry

Problem Statement

Do there exist 12 rectangular parallelepipeds P1,P2,,P12P_1,\,P_2,\ldots,P_{12} with edges parallel to coordinate axes OX,OY,OZOX,\,OY,\,OZ such that PiP_i and PjP_j have a common point iff ij±1i\ne j\pm 1 modulo 12?