3. Suppose that there are 2 classes of customers who purchase seats on an airplane: Class 1 pays $500 for each seat; and Class 2 pays $300. Suppose that the continuous demand distributions for the classes of customers are given by D₁ ~U[0, 20], D2 ~U [10, 20]. Each seat is allocated to either a Class 1 or a Class 2 customer. Once allocated, the seat can only be sold to the class of customer it is designated for. Assume that N is the total number of seats available, and N; is the number of seats allocated to Class j, for j = 1,2. For each of the following values of N, determine the optimal allocation, i.e., (N1, N2) that will maximize the expected revenue. (Note: There is a continuum of seats.) (a) N = 5 (b) N = 10 (c) N = 15 (d) N = 20