Calculations: Answer all the THREE questions Question 1: 10 marks: A retail store in Jubail, receives shipments of a particular product from Dammam and Khobar. Let a. Write the decision variables (0.5 mark) b. Write an expression for the total number of units of the product received by the retail store in Jubail. (0.5 mark) Shipments from Dammam cost 0.15 SAR per unit, shipments from Khobar cost 0.20 SAR per unit and an additional fixed cost of 1350 SAR. Develop an objective function representing the total cost of shipments to Jubail. (1 mark) d. Assuming the monthly demand at the retail store is 7000 units, develop a constraint that requires 7000 units to be shipped to Jubail. (0.5 mark) e. No more than 5000 units can be shipped from Dammam, and no more than 4000 units can be shipped from Khobar in a month. Develop constraints to model this situation. (1 marks) I. Of course, negative amounts cannot be shipped. Combine the objective function and constraints developed to state a mathematical model for satisfying the demand at the Jubail retail store at minimum cost. (2 marks) 3. If the store at Jubail sells the products received from Dammam and Khobar at 0.85 SAR per unit. What must be the quantity that the Jubail store receive to reach the break- even point assuming equal quantity of products are shipped from Dammam and Khobar? (2.5 marks) Use the Break-Even Analysis and draw the graph for (8) indicating total cost of production, total revenue, break- even point, profit, and loss. (2 marks)