Let the airline sell x tickets of executive class and y tickets of economy class.
The mathematical formulation of the given problem is as follows. Maximize z = 1000x + 600y … (1) subject to the constraints,

The feasible region determined by the constraints is as follows.

The corner points of the feasible region are A (20, 80), B (40, 160), and C (20, 180).
The values of z at these corner points are as follows.


The maximum value of z is 136000 at (40, 160). Thus, 40 tickets of executive class and 160 tickets of economy class should be sold to maximize the profit and the maximum profit is Rs 136000.