Let M be the set of five points in space, none of which four do not lie in a plane. Let R be a set of seven planes with properties:
a) Each plane from the set R contains at least one point of the setM.
b) None of the points of the set M lie in the five planes of the set R.
Prove that there are also two distinct points P, Q, P∈M, Q∈M, that the line PQ is not the intersection of any two planes from the set R. combinatoricscombinatorial geometrygeometry3D geometry