INSTRUCTION: Using linear programming graphical method solve for the optimal solution.

THE MUDDY RIVER CHEMICAL CORPORATION MUST PRODUCE EXACTLY 1,000 POUNDS OF SPECIAL MIXTURE OF PHOSPHATE AND POTASSIUM FOR A CUSTOMER. PHOSPHATE COSTS 5 PER POUND AND POTASSIUM COSTS 6 PER POUND. NO MORE THAN 300 POUNDS OF PHOSPHATE CAN BE USED, AND AT LEAST 150 POUNDS OF POTASSIUM MUST BE USED. THE PROBLEM IS TO DETERMINE THE LEAST-COST BLEND OF THE TWO INGREDIENTS.