c# - Using a variable from a different class and method into another class and method

Question

This is my main class person

public class Person
{
     public void SetAge(int n)
    {
         n = 20;
    }
    static void Main(string[] args)
    {

    }
}

and i want to access the n variabe in this inherited class student

 class student : Person
{

    public void GoToClasses()
    {
        Console.WriteLine("I am going to class");
    }
    public void ShowAge()
    {
        Console.WriteLine("My age is {0}",n);
    }
}

I tried using Person.n or SetAge(20) or SetAge(n) and it won't work !

Answer 1

public class Person
{
    public int Age {get; set;}
}

Above represents a basic object.

Use case:

Person person = new Person();
person.Age = 25;

Other object additions:

public class Person
{
    public Date BirthDate {get; set;}
    public int Age { get { return (DateTime.Now.Year - BirthDate.Year); } } //read only
}