a. Write code to define an abstract class 'Passenger" with the following attributes: account_num, fname, lname, points, num_pass (NB this is a class variable which keeps a tally on the number of passenger objects created)
There is only one constructor that receives: account_num, fname, lname, points. You must also include the necessary 'getters' and 'setters' (where appropriate) to make the attributes available. Include an abstract method 'calcPoints' that returns nothing but accepts the cost of the ticket.

b. Write a method 'toString' for the Passenger object defined above. This method must return a string stating the: account_num, fname, lname, points of the Passenger in a well structured sentence/format.

c. Define a separate class 'Regular' which is a subclass of 'Passenger'. In the constructor of this new class ensure that you invoke the constructor of the parent class 'Passenger' to initialize the inherited variables. Implement the 'calcPoints' method as follows:
1. Finds the current points by dividing the ticket cost by 10 e.g. $1500 / 10 = 150 points
2. Adds the current points to the points already accumulated
[4 marks]

d. Define a separate class 'Premium' which is a subclass of 'Passenger'. In the constructor of this new class ensure that you invoke the constructor of the parent class 'Passenger' to initialize the inherited variables. Implement the 'calcPoints' method as follows:
1. Finds the current points by dividing the ticket cost by 5 e.g $1500 / 5 = 300 points
2. Adds the current points to the points already accumulated


e. Write a separate class 'Airline' which contains a main method. In the main method you must create four objects: two Regular Passenger and two Premium Passenger. Next you are required to create an array 'pass_arr' of type 'Passenger'of size 4. Store the four account objects in this array. Finally you are required to perform the following operations on the objects:
i. Traverse the array and display the information for each Passenger by invoking the 'toString()' method you wrote in part b.
ii. Traverse the array and invoke 'calcPoints' for each Passenger to update the points earned thus far.
iii. Output the updated array.

NB. To create the 'Regular' and 'Premium' Passenger objects above you are free to 'hard code' the attribute values.