CBSE Class 12-science Answered

Let x be the number of executive class tickets and y be the number of economy class tickets sold by the airline, respectively.

                   Profit on each executive class ticket = Rs. 1000

                   Profit on x executive class tickets = Rs. 1000x

                   Profit on each economy class tickets  = Rs. 600

                   Profit on y economy class tickets  = Rs. 600y

                   Therefore, total profit = Rs. (1000x + 600y)

                   Let Z denote the total profit, then

                             Z = 1000 x + 600 y

                   As the aeroplane can carry a maximum of 200 passengers, therefore,

                        Since at least 20 executive class tickets are reserved, therefore

                                     x > 20 

                        Since  the number of tickets cannot negative, therefore

                        So, the mathematical formation of given LPP is as follows:

                                    Maximize Z = 1000 x + 600 y                   ...(1)

                        Subject to the constraints                                      

                                                                             ...(2)

                                    x  20                                                ...(3)

                                                                                   ...(4)

                        We draw the lines

                                    x + y  = 200, x = 20 and y = 4x.

                        on suitable scale in the 1^st quadrant.

            Corner point method :   The corner points of the feasible region (shaded) ABC are
A(20, 80), B (40, 160) and C (20, 180)

            Note that the coordinates of A, B and C are obtained by solving x = 20, y = 4x;  y = 4x and x+ y = 200;  x = 20 and x + y = 200.

                        The value of the objective function Z at these points are given in the following table:

            From the table, we see that the maximum value of Z is 136000 at the point (40, 160).

            Thus, x = 40, y = 160 is the optimal of the given LPP. Hence, the airline should sell 40 executive class tickets and 160 economy class tickets to maximize profit.  The maximum profit is Rs. 1,36,000.