SOLVED

Section 7  Linear Programming Applications 1) In linear programming, statements such as “the blend must consist of at least 10% of ingredient A, at least 30% of ingredient B, and no more than 50% of ingredient C” can be made into valid constraints even though the percentages do not add up to 100 percent. 2) The diet problem is known in agricultural applications as the: A) fertilizer problem. B) feed-mix problem. C) crop-rotation problem. D) egg-choice problem. E) genetic-transformation problem. 3) A financial advisor is about to build an investment portfolio for a client who has $100,000 to invest. The four investments available are A, B, C, and D. Investment A will earn 4 percent and has a risk of two “points” per $1,000 invested. B earns 6 percent with 3 risk points; C earns 9 percent with 7 risk points; and D earns 11 percent with a risk of 8. The client has put the following conditions on the investments: A is to be no more than one-half of the total invested. A cannot be less than 20 percent of the total investment. D cannot be less than C. Total risk points must be at or below 1,000. Let A be the amount invested in investment A, and define B, C, and D similarly. Formulate the linear programming model. 4) Tom is a habitual shopper at garage sales. Last Saturday he stopped at one where there were several types of used building materials for sale. At the low prices being asked, Tom knew that he could resell the items in another town for a substantial gain. Four things stood in his way: he could only make one round trip to resell the goods; his pickup truck bed would hold only 1000 pounds; the pickup truck bed could hold at most 70 cubic feet of merchandise; and he had only $200 cash with him. He wants to load his truck with the mix of materials that will yield the greatest profit when he resells them. Item Cubic feet per unit Price per unit Weight per unit Can resell for 2 × 4 studs 1 $0.10 5 pounds $0.80 4 × 8 plywood 3 $0.50 20 pounds $3.00 Concrete blocks 0.5 $0.25 10 pounds $0.75 Formulate this problem as a linear program. 5) Phil Bert’s Nuthouse is preparing a new product, a blend of mixed nuts. The product must be at most 50 percent peanuts, must have more almonds than cashews, and must be at least 10 percent pecans. The blend will be sold in one-pound bags. Phil’s goal is to mix the nuts in such a manner that all conditions are satisfied and the cost per bag is minimized. Peanuts cost $1 per pound. Cashews cost $3 per pound. Almonds cost $5 per pound and pecans cost $6 per pound. Formulate this problem as a linear program.