gistfile1.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication8
{
  public class Person
	{
		public string FirstName { get; set; }
		public string LastName { get; set; }
		public virtual string GetDisplayName()
		{
			return FirstName + " " + LastName;
		}
	}

	public class Employee : Person
	{
		private decimal salary = 0;
		public decimal Salary
		{
			get
			{
				return salary;
			}
		}

		public void GiveRaise(decimal raise)
		{
			salary = salary + raise;
		}
	}

	public class Manager : Employee
	{
		public override string GetDisplayName()
		{
			return "The Cheez - " + base.GetDisplayName();
		}
	}

	class Program
	{
		static void Main(string[] args)
		{
			var customers = new List<Person>
				{
					new Person { FirstName = "Bob", LastName = "Smith" },
					new Person { FirstName = "Sue", LastName = "Smith" },
					new Person { FirstName = "Mary", LastName = "Allen" }
				};

			var employees = new List<Employee>
				{
					new Employee { FirstName = "Jimbo", LastName = "Jambo" },
					new Employee { FirstName = "Emeril", LastName = "McGravitz" }
				};

			var manager = new Manager { FirstName = "Scrooge", LastName = "McDuck" };

			var everyone = new List<Person>(customers);
			everyone.AddRange(employees);
			everyone.Add(manager);

			foreach (var person in everyone)
			{
				Console.WriteLine(person.GetDisplayName());
			}
		}
	}
}