Lesson 5: Computational Problems

ISE 302-7 (Fall '17)

Lesson: Solving LPs Using Excel - Lab

Objectives:

1. Setup and solve LPs using Excel's solver add-in. 2. Perform "quick and dirty" sensitivity analysis using Excel and solver.

Assignment:

Peruse Excel help index using keyword "solver".

Homework:

1. The Apex Television Company has to decide on the number of 27- and 20-inch sets to be produced at one of its factories. Market research indicates that at most 40 of the 27-inch sets and 10 of the 20-inch set can be sold per month. The maximum number of work-hours available is 500 per month. A 27-inch set requires 20 work-hours and a 20-inch set requires 10 work-hours. Each 27-inch set sold produces a profit of $120 and each 20-inch set produces a profit of $80. A wholesaler has agreed to purchase all the television sets produces if the numbers do not exceed the maxima indicated by market research. a) Formulate a linear programming model for this problem b) Solve using Excel c) How many 27-inch and 20-inch televisions would you produce to maximize profit if the time to manufacture the 20-inch televisions increases to 12 work hours? d) How many 27-inch and 20-inch televisions would you produce to maximize profit if the time to manufacture the 20-inch televisions increases to 14 work hours?

2. The Metalco Company desires to blend a new alloy of 40 percent tin, 35 percent zinc, and 25 percent lead from several available alloys having the following properties:

Alloy Property 1 2 3 4 5 Percentage of tin 60 25 45 20 50 Percentage of zinc 10 15 45 50 40 Percentage of lead 30 60 10 30 10 Cost ($/lb) 22 20 25 24 27 The objective is to determine the proportions of these alloys that should be blended to produce the new alloy at a minimum cost. a) Formulate a linear programming model for this problem. b) Solve using Excel.