We have a set of nodes, where each node is both a customer and a potential facility location, i.e., I = J. The horizontal and vertical coordinates for node i is given by ai and bi , respectively. The demand is denoted by hi for each customer, and the fixed cost is fj for opening facility j. The transportation cost is cij between each pair of nodes i and j. Note that the transportation costs equal 10 times the Euclidean distance between the nodes (the Euclidean distance for two points (a1, b1) and (a2, b2) is defined as (a1 a2) 2 (b1 b2) 2, hence cij = 10 (a1 a2) 2 (b1 b2) 2). (a) Please formulate this problem as UFLP, where the objective is to minimize the total cost (fixed and transportation costs), and the decision variables are number and locations of facilities and assignments of customers to facilities. Please only use the notations fj , hi , and cij in this part without substituting the numerical values. (b) Use the greedy-add heuristic to solve the above UFLP, where the specific data on coordinate (ai , bi), demand hi , and fixed cost fj