unit CarTruck;

interface
uses Vehicles;
type

   Car = object(Vehicle)

      Passenger_Load : integer;

      constructor Init(In_Wheels : integer;

                       In_Weight : real;

                       People    : integer);

      function Passengers : integer;

   end;
   Truck = Object(Vehicle)

      Passenger_Load : integer;

      Payload        : real;

      constructor Init(People : integer;

                       Max_Load : real;

                       In_Wheels : integer;

                       In_Weight : real);

      function Efficiency : real;

      function Wheel_Loading :real;

   end;
implementation
   constructor Car.Init(In_Wheels : integer;

                        In_Weight : real;

                        People    : integer);

   begin

      Wheels := In_Wheels;

      Weight := In_Weight;

      Passenger_Load := People;

   end;
   function Car.Passengers : integer;

   begin

      Passengers := Passenger_Load;

   end;
   constructor Truck.Init(People : integer;

                          Max_Load : real;

                          In_Wheels : integer;

                          In_Weight : real);

   begin

      Passenger_Load := People;

      Payload := Max_Load;

      Vehicle.Init(In_Wheels, In_Weight);

   end;
   function Truck.Efficiency : real;

   begin

      Efficiency := 100.0 * Payload / (Payload + Weight);

   end;
   function Truck.Wheel_Loading : real;

   begin

      Wheel_Loading := (Weight + Payload)/Wheels;

   end;
end.


 Result of execution

(This file cannot be executed)