Missouri Mineral Products (MMP) purchases two unprocessed ores from Bolivia Mining, which it uses in the production of various compounds. Its current needs are for 800 pounds copper, 600 pounds of zinc, and 500 pounds of iron. The amount of each mineral found in each 100 pounds of the unprocessed ores and MMP's cost per 100 pounds are given in the following table.

ORE copper per zinc per iron per waste per cost per
100 lbs 100 lbs 100 lbs 100 lbs 100 lbs
La Paz Ore 20 20 20 40 $100
Sucre Ore 40 25 10 25 $140

The objective is to determine the amount of each ore that should be purchased in order to minimize the total purchasing cost.

a) Formulate the linear programming model for the problem.

b) Use the Graphical method to find the optimal solution. Show all steps.

c) Use Excel Solver to find the optimal solution. Copy and paste your spreadsheet and the Answer report in its entirety from Excel. Remember to not delete/modify any part of the Answer Report.