in this problem, suppliers offer all-units quantity discounts. For example, if the buyer purchases less than 500 units from Supplier 1, he needs to pay $6.5/unit; if the order quantity from Supplier 1 is between 500 and 800, the buyer needs to pay $6.0/unit, and so on. Also, the buyer cannot buy more than 1200 units from supplier 1. Assume that Q is the order quantity Formulate this supplier selection problem by using mixed integer linear programming and calculate the optimum order quantities from the suppliers. Rubric Formulate the price breaks (Excel & Solver) 2 points Formulate the objective function (Excel & Solver) 1.5 Points Determine the decision variables (excel& solver) 0.5 Point Demand constraint (excel& solver) 0.5 Point Final solution 0.5 Point