MathDB
Putnam 1980 B2

Source: Putnam 1980

April 1, 2022
Putnam3D geometry

Problem Statement

Let SS be the solid in three-dimensional space consisting of all points (x,y,z)(x,y,z) satisfying the following six simultaneous conditions: x,y,z0,    x+y+z11,    2x+4y+3z36,    2x+3z44. x,y,z \geq 0, \;\; x+y+z\leq 11, \;\; 2x+4y+3z \leq 36, \;\; 2x+3z \leq 44. a) Determine the number VV of vertices of S.S. b) Determine the number EE of edges of S.S. c) Sketch in the bcbc-plane the set of points (b,c)(b, c) such that (2,5,4)(2,5,4) is one of the points (x,y,z)(x, y, z) at which the linear function bx+cy+zbx + cy + z assumes its maximum value on S.S.