Linear Programming Problems Section 3.2 Linear Programming Problems

Linear Programming Problem A linear programming problem consists of a linear objective function to be maximized or minimized, subject to certain constraints in the form of linear equalities or inequalities.

Ex. A small company consisting of two carpenters and a finisher produce and sell two types of tables: type A and type B. The type-A table will result in a profit of $50, and each type-B table will result in a profit of $54. A type-A table requires 3 hours of carpentry and 1 hour of finishing. A type-B table requires 2 hours of carpentry and 2 hours of finishing. Each day there are 16 hours available for carpentry and 8 hours available for finishing. How many tables of each type should be made each day to maximize profit?

Organize the Information: Table A Table B Time Carpentry 3 2 16 hours Finishing 1 8 hours Profit/table $50 $54 Let x = # type A and y = # type B. The Profit to Maximize (in dollars) is given by: P = 50x + 54y

The constraints are given by: Carpentry Finishing Also so that the number of units is not less than 0: So we have:

Ex. A particular company manufactures specialty chairs in two plants Ex. A particular company manufactures specialty chairs in two plants. Plant I has an output of at most 150 chairs/month. Plant II has an output has an output of at most 120 chairs/month. The chairs are shipped to 3 possible warehouses - A, B, and C. The minimum monthly requirements for warehouses A, B, and C are 70, 70, and 80 respectively. Shipping charges from plant I (to A, B, and C) are $30, $32, and $38/chair and from plant II (to A, B, and C) are $32, $28, $26. How many chairs should be shipped to each warehouse to minimize the monthly shipping cost?

Organize the Information: Plant A B C I x1 x2 x3 150 II x4 x5 x6 120 Number of Chairs Plant A B C Max. Prod. I x1 x2 x3 150 II x4 x5 x6 120 Min. 70 80 Cost to Ship Plant A B C I 30 32 38 II 28 26

We want to minimize the cost function: C = 30x1 + 32x2 + 38x3 + 32x4 + 28x5 + 26x6 Production constraints: Plant I Plant II Warehouse constraints: A B C

So the problem is: Minimize: Subject to: C = 30x1 + 32x2 + 38x3 + 32x4 + 28x5 + 26x6