CHAPTER 3 LINEAR PROGRAMMING: FORMULATION AND APPLICATIONS SOLUTION TO SOLVED PROBLEMS 3.S1 Farm Management Dwight and Hattie have run the family farm for over thirty years. They are currently planning the mix of crops to plant on their 120-acre farm for the upcoming season. The table below gives the labor hours and fertilizer required per acre, as well as the total expected profit per acre for each of the potential crops under consideration. Dwight, Hattie, and their children can work at most 6,500 total hours during the upcoming season. They have 20 tons of fertilizer available. What mix of crops should be planted to maximize the family’s total profit. Formulate and solve a linear programming model in a spreadsheet. Crop Labor Required (hours per acre) Fertilizer Required (tons per acre) Expected Profit (per acre) Oats 50 1.5 $500 Wheat 60 2 $600 Corn 105 4 $950 This is a resource-allocation problem. The activities are the planting of the three crops and the limited resources are land, labor, and fertilizer. We will therefore build a spreadsheet following the template for resource-allocation problems in Figure 3.4. Start by entering the data. The data for this problem are the labor required, fertilizer required, and expected profit for each crop (per acre). Following the template, the data in the spreadsheet would be entered as displayed below, where range names of ProfitPerAcre (C4:E4) and TotalAvailable (H7:H9) are assigned to the corresponding data cells. B 3 4 5 6 7 8 9 Profit (per acre) Resources Land (acres) Labor (hours) Fertilizer (tons) C Oats $500 D Wheat $600 E Corn $950 Resources Used per Acre 1 1 1 50 60 105 1.5 2 4 1 F G H Total Available 120 6500 200 The decisions to be made in this problem are how many acres of each crop to plant. Therefore, we add three changing cells in C12:E12 with range name AcresPlanted. The values in AcresPlanted (C12:E12) will eventually be determined by the Solver. For now, an arbitrary value of 1 is entered for each crop. B 3 4 5 6 7 8 9 10 11 12 Profit (per acre) Resources Land (acres) Labor (hours) Fertilizer (tons) Acres Planted C Oats $500 D Wheat $600 E Corn $950 F G Total Available 120 6500 200 Resources Used per Acre 1 1 1 50 60 105 1.5 2 4 1 1 H 1 The goal is to maximize the family’s total profit. Thus, the target cell should calculate the total profit. In this case, the total profit will be Total Profit = ($500)(acres of oats) + ($600)(acres of wheat) + ($950)(acres of corn) or Total Profit = SUMPRODUCT(ProfitPerAcre, AcresPlanted). This formula is entered into cell H12. With 1 acre of each crop planted, the total cost would be ($500)(1) + ($600)(1) + ($950)(1) = $2,050. B 3 4 5 6 7 8 9 10 11 12 Profit (per acre) Resources Land (acres) Labor (hours) Fertilizer (tons) Acres Planted C Oats $500 D Wheat $600 E Corn $950 Resources Used per Acre 1 1 1 50 60 105 1.5 2 4 1 1 1 11 12 2 F G H Total Available 120 6500 200 Total Profit $2,050 H Total Profit =SUMPRODUCT(ProfitPerAcre,AcresPlanted) The functional constraints in this problem involve the limited resources of land, labor, and fertilizer. Given the AcresPlanted (the changing cells in C12:E12), we calculate the total resources used in TotalUsed (cells F7:F9). For land, this will be =SUMPRODUCT(C7:E7, AcresPlanted). Using a range name or an absolute reference for the acres planted, this formula can be copied into cells F8:F9 to calculate the amount of labor and fertilizer used. The total resources used must be <= TotalAvailable (H7:H9), as indicated by the <= in G7:G9. B 3 4 5 6 7 8 9 10 11 12 Profit (per acre) Resources Land (acres) Labor (hours) Fertilizer (tons) Acres Planted C Oats $500 D Wheat $600 E Corn $950 Resources Used per Acre 1 1 1 50 60 105 1.5 2 4 1 1 1 5 6 7 8 9 3 F Total Used 3 215 8 G H <= <= <= Total Available 120 6500 200 Total Profit $2,050 F Total Used =SUMPRODUCT(C7:E7,AcresPlanted) =SUMPRODUCT(C8:E8,AcresPlanted) =SUMPRODUCT(C9:E9,AcresPlanted) The Solver information and solved spreadsheet are shown below. A 1 2 3 4 5 6 7 8 9 10 11 12 B C D E Oats $500 Wheat $600 Corn $950 G H <= <= <= Total Available 120 6500 200 Farm Management Profit (per acre) Resources Land (acres) Labor (hours) Fertilizer (tons) Acres Planted Resources Used per Acre 1 1 1 50 60 105 1.5 2 4 80 40 F Total Used =SUMPRODUCT(C7:E7,AcresPlanted) =SUMPRODUCT(C8:E8,AcresPlanted) =SUMPRODUCT(C9:E9,AcresPlanted) Total Used 120 6,400 200 Total Profit $64,000 0 Range Nam e AcresPla nted Profi tPerAcre TotalAvai labl e TotalProfit TotalUsed 5 6 7 8 9 F 11 12 Cells C12:E1 2 C4:E4 H7:H9 H12 F7:F9 H Total Profit =SUMPRODUCT(ProfitPerAcre,AcresPlanted) Thus, oats should be planted on 80 acres and wheat on 40 acres, while not planting any corn, with a resulting total profit of $64,000. 4 3.S2 Diet Problem The kitchen manager for Sing Sing Prison is trying to decide what to feed its prisoners. She would like to offer some combination of milk, beans, and oranges. The goal is to minimize cost, subject to meeting the minimum nutritional requirements imposed by law. The cost and nutritional content of each food, along with the minimum nutritional requirements, are shown below. What diet should be fed to each prisoner? Formulate and solve a linear programming model in a spreadsheet. Milk (gallons) 3.2 1.12 32.0 2.00 Niacin (mg) Thiamin (mg) Vitamin C (mg) Cost ($) Navy Beans (cups) 4.9 1.3 0.0 0.20 Oranges (large Calif. Valencia) 0.8 0.19 93.0 0.25 Minimum Daily Requirement 13.0 1.5 45.0 This is a cost-benefit-trade-off problem. The activities are the quantities of food to feed each prisoner and the required benefits are the minimum nutritional requirements. We will therefore build a spreadsheet following the template for cost-benefit-trade-off problems in Figure 3.6. Start by entering the data. The data for this problem are the nutrient content of each food, the minimum daily requirement for each nutrient, and the cost of each food. Following the template, the data in the spreadsheet would be entered as displayed below, where range names of UnitCost (C5:E5), NutritionalContents (C9:E11), and MinimumRequirement (H9:H11) are assigned to the corresponding data cells. B 3 4 5 6 7 8 9 10 11 Unit Cost Niacin Thiamin Vitamin C C Milk (gal.) $2.00 D Beans (cups) $0.20 E F G H Oranges $0.25 Nutritional Contents (mg) 3.2 4.9 0.8 1.12 1.3 0.19 32 0 93 5 Minimum Requirement 13 1.5 45 The decisions to be made in this problem are how much of each food type should be fed to each prisoner. Therefore, we add three changing cells in C13:E13, with range name Quantity. The values in Quantity (C13:E13) will eventually be determined by the Solver. For now, an arbitrary value of 1 is entered for each food type. The goal is to minimize the total cost per prisoner. Thus, the target cell should calculate this cost: Total Cost = ($2)(gallons of milk) + ($0.20)(cups of beans) + ($0.25)(number of oranges) or Total Cost = SUMPRODUCT(UnitCost, Quantity). This formula is entered into cell H14. B 3 4 5 6 7 8 9 10 11 12 13 14 Unit Cost Niacin Thiamin Vitamin C Quantity (per prisoner) C Milk (gal.) $2.00 D Beans (cups) $0.20 E G H Oranges $0.25 Nutritional Contents (mg) 3.2 4.9 0.8 1.12 1.3 0.19 32 0 93 1 F 1 1 13 14 6 Minimum Requirement 13 1.5 45 Total Cost $2.45 H Total Cost =SUMPRODUCT(UnitCost,Quantity) The functional constraints in this problem involve the minimum daily requirement of each nutrient. Given the amount of food fed each prisoner (the changing cells in C13:E13), we calculate the total resources used in F9:F11. For niacin, this will be =SUMPRODUCT(C9:E9, $C$13:$E$13). Using an absolute reference for the acres planted, this formula can be copied into cells F10-F11 to calculate the thiamin and vitamin C. The benefit achieved (total of each nutrient) must be >= the minimum needed (H9:H11), as indicated by the >= in G9:G11. B 3 4 5 6 7 8 9 10 11 12 13 14 Unit Cost Niacin Thiamin Vitamin C Quantity (per prisoner) C Milk (gal.) $2.00 D Beans (cups) $0.20 E G H Oranges $0.25 Nutritional Contents (mg) 3.2 4.9 0.8 1.12 1.3 0.19 32 0 93 1 F 1 1 7 8 9 10 11 7 Total Nutrients 8.9 >= 2.610 >= 125 >= Minimum Requirement 13 1.5 45 Total Cost $2.45 F Total Nutrients =SUMPRODUCT(C9:E9,Quantity) =SUMPRODUCT(C10:E10,Quantity) =SUMPRODUCT(C11:E11,Quantity) The Solver information and solved spreadsheet are shown below. A 1 2 3 4 5 6 7 8 9 10 11 12 13 14 B C D E Beans (cups) $0.20 Oranges $0.25 G H The Prison Diet Problem Unit Cost Niacin Thiamin Vitamin C Quantity (per prisoner) Milk (gal.) $2.00 Nutritional Contents (mg) 3.2 4.9 0.8 1.12 1.3 0.19 32 0 93 0 2.574 F Total Nutrients =SUMPRODUCT(C9:E9,Quantity) =SUMPRODUCT(C10:E10,Quantity) =SUMPRODUCT(C11:E11,Quantity) Total Nutrients 13 >= 3.438 >= 45 >= 0.484 Range Name Mini mumRequirem ent Nutri tionalContents Quantity TotalCos t TotalNutrients UnitCost 7 8 9 10 11 F 13 14 Minimum Requirement 13 1.5 45 Total Cost $0.64 Cells H9:H11 C9:E11 C13:E13 H14 F9:F11 C5:E5 H Total Cost =SUMPRODUCT(UnitCost,Quantity) Thus, each prisoner should be fed a daily average of 2.574 cups of beans and 0.484 oranges for a total cost of $0.64. 8 3.S3 Cutting Stock Problem Decora Accessories manufactures a variety of bathroom accessories, including decorative towel rods and shower curtain rods. Each of the accessories includes a rod made out of stainless steel. However, many different lengths are needed: 12”, 18”, 24”, 40”, and 60”. Decora purchases 60” rods from an outside supplier and then cuts the rods as needed for their products. Each 60” rod can be used to make a number of smaller rods. For example, a 60” rod could be used to make a 40” and an 18” rod (with 2” of waste), or 5 12” rods (with no waste). For the next production period, Decora needs 25 12” rods, 52 18” rods, 45 24” rods, 30 40” rods, and 12 60” rods. What is the fewest number of 60” rods that can be purchased to meet their production needs? Formulate and solve an integer programming model in a spreadsheet. This is a cost-benefit-trade-off problem. For each length of rod, the required benefit is obtaining the minimum number needed of those rods. Each possible way of cutting a 60” rod will represent an activity. For example, a 60” rod can be cut into 5 12” rods, or 3 12” rods and an 18” rod (with 6” scrap), or 3 12” rods and a 24” rod, etc. We will build a spreadsheet following the template for cost-benefit-trade-off problems in Figure 3.6. Start by entering the data. The data for this problem are the total length of the uncut rods, the minimum number of each rod length required and, for each possible pattern of cutting a 60” rod, the number of each length rod created. There are 11 possible patterns of cutting a 60” rod that either leave no scrap or an unusable piece of scrap (i.e., less than 12”). Following the template, the data in the spreadsheet would be entered as displayed, where range names of UncutRodLength (F3), MinimumRequirement (P7:P11), and Waste (C12:M12) are assigned to the corresponding data cells. 3 4 5 6 7 8 9 10 11 12 12 B C D Length of Uncut Rods Length of Cut Rod 12 18 24 40 60 Waste B Waste 1 5 2 3 1 E F G 60 3 3 4 2 2 1 0 6 0 0 H I Pattern 5 6 7 1 1 1 1 1 2 1 6 0 8 J K L M 8 9 10 11 3 2 1 1 1 6 0 2 1 0 N O P Minimum Requirement 25 52 45 30 12 C =UncutRodLength-SUMPRODUCT($B$7:$B$11,C7:C11) 9 The decisions to be made in this problem are how many rods should be cut into each of the possible patterns. Therefore, we add 11 changing cells in C14:M14, with range name PatternQuantity. The values in PatternQuantity (C14:M14) will eventually be determined by the Solver. For now, an arbitrary value of 1 is entered for each pattern. B 3 4 5 6 7 8 9 10 11 12 13 14 C D E F G Length of Uncut Rods 60 Length of Cut Rod 12 18 24 40 60 Waste Pattern Quantity 1 5 2 3 1 3 3 4 2 2 1 H I Pattern 5 6 7 1 1 1 1 1 2 1 J K L M 8 9 10 11 3 2 1 1 N O Minimum Needed 25 52 45 30 12 1 0 6 0 0 6 0 8 6 0 2 1 0 1 1 1 1 1 1 1 1 1 1 1 P The goal is to minimize the total number of 60” (uncut) rods needed. This is just the sum of the changing cells: Total Uncut Rods needed = SUM(PatternQuantity). This formula is entered into cell P14. B 3 4 5 6 7 8 9 10 11 12 13 14 C D E F G Length of Uncut Rods 60 Length of Cut Rod 12 18 24 40 60 Waste Pattern Quantity 1 5 2 3 1 3 3 4 2 2 1 H I Pattern 5 6 7 1 1 1 1 1 2 1 J K L M 8 9 10 11 3 2 1 1 N 6 0 0 6 0 8 6 0 2 1 0 1 1 1 1 1 1 1 1 1 1 1 Total Uncut Rods Needed 11 13 14 10 P Minimum Needed 25 52 45 30 12 1 0 O P Total Uncut Rods Needed =SUM(PatternQuantity) The functional constraints in this problem require that the number of cut rods of each length must be at least the minimum number needed. Given PatternQuantity (the changing cells in C14:M14), we calculate the total number of each rod length produced in TotalProduced (N7:N11). For 12” rods, this will be =SUMPRODUCT(C7:M7, PatternQuantity). Using a range name or absolute reference for the quantity of each pattern, this formula can be copied into cells N8:N11 to calculate the total number of other lengths created. For each rod length, the benefit achieved (the total number of that rod length cut) must be >= MinimumRequirement (P7:P11), as indicated by the >= in O7:O11. 3 4 5 6 7 8 9 10 11 12 13 14 B C D E F G Length of Uncut Rods 60 Length of Cut Rod 12 18 24 40 60 Waste 1 5 2 3 1 3 3 4 2 2 1 H I Pattern 5 6 7 1 1 1 1 1 2 1 J K L M 8 9 10 11 3 2 1 1 1 0 6 0 0 6 0 8 6 0 2 1 0 Pattern Quantity 1 1 1 1 1 1 1 1 1 1 1 5 6 7 8 9 10 11 11 N Total Produced 16 10 5 2 1 O P >= >= >= >= >= Minimum Needed 25 52 45 30 12 Total Uncut Rods Needed 11 N Total Produced =SUMPRODUCT(C7:M7,PatternQuantity) =SUMPRODUCT(C8:M8,PatternQuantity) =SUMPRODUCT(C9:M9,PatternQuantity) =SUMPRODUCT(C10:M10,PatternQuantity) =SUMPRODUCT(C11:M11,PatternQuantity) Also, an integer number of each pattern must be cut. Therefore, we constrain the changing cells to be integer. The Solver information and solved spreadsheet are shown below. A 1 2 3 4 5 6 7 8 9 10 11 12 13 14 B C D E F G H I J L M N O P Cutting Stock Problem Length of Uncut Rods 60 Length of Cut Rod 12 18 24 40 60 Waste 1 5 2 3 1 3 3 4 2 2 1 Pattern Quantity Pattern 5 6 7 1 1 1 1 1 2 1 8 3 0 6 0 0 6 0 8 6 2 0 0 0 0 17 0 0 Range Na me Mini mumNee ded PatternQua ntity To talProduced To talRod sNeede d UncutRodL ength Wa ste 5 6 7 8 9 10 11 12 K B Waste Total Minimum 10 11 Produced Needed 27 >= 25 2 1 52 >= 52 1 45 >= 45 1 30 >= 30 1 12 >= 12 0 2 0 Total Uncut Rods Needed 11 30 12 72 9 Cells P7:P11 C14:M1 4 N7:N11 P14 F3 C12:M1 2 N Total Produced =SUMPRODUCT(C7:M7,PatternQuantity) =SUMPRODUCT(C8:M8,PatternQuantity) =SUMPRODUCT(C9:M9,PatternQuantity) =SUMPRODUCT(C10:M10,PatternQuantity) =SUMPRODUCT(C11:M11,PatternQuantity) C =UncutRodLength-SUMPRODUCT($B$7:$B$11,C7:C11) 13 14 P Total Uncut Rods Needed =SUM(PatternQuantity) Thus, PatternQuantity (C14:M14) show the number of rods that should be cut into the respective patterns. TotalRodsNeeded (P14) indicates that a total of 72 uncut rods are needed. 12 3.S4 Bidding for Classes In the MBA program at a prestigious university in the Pacific Northwest, students bid for electives in the second year of their program. Each student has 100 points to bid (total) and must take two electives. There are four electives available: Management Science, Finance, Operations Management, and Marketing. Each class is limited to 5 students. The bids submitted for each of the 10 students are shown in the table below. Management Science 60 20 45 50 30 50 70 25 35 60 Student George Fred Ann Eric Susan Liz Ed David Tony Jennifer Finance 10 20 45 20 30 50 20 25 15 10 Operations Management 10 40 5 5 30 0 10 35 35 10 Marketing 20 20 5 25 10 0 0 15 15 20 a. Formulate and solve a spreadsheet model to determine an assignment of students to classes so as to maximize the total bid points of the assignments. This is a special kind of assignment problem. The assignees are the students and the tasks are the classes. Each student is assigned to take two classes. Each class has a limit of five students. Start by entering the data. The data for this problem are the bid points for each student for each class, where the corresponding data cells are assigned a range name of Points (C5:F14). B 3 4 5 6 7 8 9 10 11 12 13 14 Points George Fred Ann Eric Susan Liz Ed David Tony Jennifer C Management Science 60 20 45 50 30 50 70 25 35 60 D Finance 10 20 45 20 30 50 20 25 15 10 13 E Operations Management 10 40 5 5 30 0 10 35 35 10 F Marketing 20 20 5 25 10 0 0 15 15 20 The decisions to be made in this problem are whether or not to assign each student to each class. Therefore, a table of changing cells is created for each student and class combination in C18:F27, and given a range name of Assignment. The values in Assignment (C18:F27) will eventually be determined by the Solver. For now, arbitrary values of 0 and 1 are entered. B 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Points George Fred Ann Eric Susan Liz Ed David Tony Jennifer C Management Science 60 20 45 50 30 50 70 25 35 60 Assignment George Fred Ann Eric Susan Liz Ed David Tony Jennifer Management Science 1 0 1 0 1 0 1 0 1 0 D Finance 10 20 45 20 30 50 20 25 15 10 E Operations Management 10 40 5 5 30 0 10 35 35 10 Marketing 20 20 5 25 10 0 0 15 15 20 Finance 0 1 0 1 0 1 0 1 0 1 Operations Management 1 0 1 0 1 0 1 0 1 0 Marketing 0 1 0 1 0 1 0 1 0 1 14 F The goal is to maximize the total bid points of the assignments. Total Bid Points = SUMPRODUCT(Points, Assignment). This formula is entered into cell I29. B 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Points George Fred Ann Eric Susan Liz Ed David Tony Jennifer C Management Science 60 20 45 50 30 50 70 25 35 60 Assignment George Fred Ann Eric Susan Liz Ed David Tony Jennifer Management Science 1 0 1 0 1 0 1 0 1 0 D Finance 10 20 45 20 30 50 20 25 15 10 E Operations Management 10 40 5 5 30 0 10 35 35 10 F Marketing 20 20 5 25 10 0 0 15 15 20 Finance 0 1 0 1 0 1 0 1 0 1 Operations Management 1 0 1 0 1 0 1 0 1 0 Marketing 0 1 0 1 0 1 0 1 0 1 G H Total Points 29 I 535 H I Total Points =SUMPRODUCT(Points,Assignment) 15 The functional constraints in this problem are that each student must be assigned to two classes, each class is limited to five students, and each student can take each class at most once. The number of classes a student is assigned to is just the sum of the row of changing cells for each student. For example, for George it is =SUM(C18:F18). This formula is copied into G18:G27. The number of students assigned to a class is the sum of the column of changing cells for each class. For example, for Management Science it is =SUM(C18:C27). This formula is copied into C28:F28. B 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 C Management Points Science George 60 Fred 20 Ann 45 Eric 50 Susan 30 Liz 50 Ed 70 David 25 Tony 35 Jennifer 60 Management Science 1 0 1 0 1 0 1 0 1 0 5 <= Capacity 5 Assignment George Fred Ann Eric Susan Liz Ed David Tony Jennifer D G Finance 10 20 45 20 30 50 20 25 15 10 E F Operations Management Marketing 10 20 40 20 5 5 5 25 30 10 0 0 10 0 35 15 35 15 10 20 Finance 0 1 0 1 0 1 0 1 0 1 5 <= 5 Operations Management Marketing 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 5 5 <= <= 5 5 Total Classes 2 2 2 2 2 2 2 2 2 2 H I = = = = = = = = = = Classes to Take 2 2 2 2 2 2 2 2 2 2 Total Points 535 K 16 17 18 19 20 21 22 23 24 25 26 27 28 Total Classes =SUM(C18:F18) =SUM(C19:F19) =SUM(C20:F20) =SUM(C21:F21) =SUM(C22:F22) =SUM(C23:F23) =SUM(C24:F24) =SUM(C25:F25) =SUM(C26:F26) =SUM(C27:F27) B C D E F Total in Class =SUM(C18:C27) =SUM(D18:D27) =SUM(E18:E27) =SUM(F18:F27) 16 The Solver information and solved spreadsheet are shown below. A 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 B C D E F Management Science 60 20 45 50 30 50 70 25 35 60 Finance 10 20 45 20 30 50 20 25 15 10 Operations Management 10 40 5 5 30 0 10 35 35 10 Marketing 20 20 5 25 10 0 0 15 15 20 Management Science 1 0 1 0 0 1 1 0 0 1 5 <= 5 Finance 0 0 1 1 1 1 0 1 0 0 5 <= 5 Operations Management 0 1 0 0 1 0 1 1 1 0 5 <= 5 Marketing 1 1 0 1 0 0 0 0 1 1 5 <= 5 G H I = = = = = = = = = = Classes to Take 2 2 2 2 2 2 2 2 2 2 J K Bidding for Classes Points George Fred Ann Eric Susan Liz Ed David Tony Jennifer Assignment George Fred Ann Eric Susan Liz Ed David Tony Jennifer Total in Class Capacity Range Na me As sign ment Capa city Clas sesToTake Poi nts Stu dentPoints To talCla sses To talInClass To talPo ints G 16 17 18 19 20 21 22 28 Total Classes 2 2 2 2 2 2 2 2 2 2 Total Points 705 Cells C18:F27 C30:F30 I1 8:I2 7 C5:F14 K18 :K27 G18:G2 7 C28:F28 I2 9 K Total Classes =SUM(C18:F18) =SUM(C19:F19) =SUM(C20:F20) : : 16 17 18 19 20 21 22 Student Points =SUMPRODUCT(C5:F5,C18:F18) =SUMPRODUCT(C6:F6,C19:F19) =SUMPRODUCT(C7:F7,C20:F20) : : B C D E F Total in Class =SUM(C18:C27) =SUM(D18:D27) =SUM(E18:E27) =SUM(F18:F27) 29 H I Total Points =SUMPRODUCT(Points,Assignment) 17 Student Points 80 60 90 45 60 100 80 60 50 80 Thus, the 1’s in Assignment (C18:F27) show the assignments that should be made, achieving a total of 705 points. b. Does the resulting solution seem like a fair assignment? No. For example, Eric did not get into Management Science despite bidding 50 points, while Ann got in with only 45 points. Also, Eric got into classes worth only 45 total bid points to him while Liz got classes worth 100 bid points to her. c. Which alternative objectives might lead to a fairer assignment? Perhaps maximizing the minimum total number of bid points achieved by each student. 18