Passenger.java

public class Passenger {
    public String name;
    public int age;
    public int preferredAltitude;

    public Passenger(int age, String name, int preferredAltitude) {
        this.age = age;
        this.name = name;
        this.preferredAltitude = preferredAltitude;
    }

    public String toString() {
        return "The name of the passenger is: " + name + "\nThe age of the passenger is: " + age + "\nThe preferred altitude of the passenger is: " + preferredAltitude;
    }
    public String setPreferredAltitude(int altitude) {
        return "The new preferred altitude is: " + altitude;
    }
}