using System;

using System.Collections.Generic;

using System.Linq;

​

// order

// CustomerName

// product total 

// tax ->

// total p+t

​

// lista orders

​

// sort -> total, CustomerName

​

public class Order

{

    public string CustomerName { get; set; }

    public double ProductTotal { get; set; }

    public double Tax { get => ProductTotal * 0.19; }

    public double Total { get => ProductTotal + Tax; }

    public override string ToString() =>  return $"Order {CustomerName} {ProductTotal} {Tax} {Total}";

}

public class Program

{   

    public static void Main()

    {

        var orders = new List<Order>{ 

            new Order { CustomerName = "Joe", ProductTotal = 100 },

            new Order { CustomerName = "Ion", ProductTotal = 89 },

            new Order { CustomerName = "Georg", ProductTotal = 120 },

            new Order { CustomerName = "George", ProductTotal = 5 }

        };

        var result = orders.OrderBy( order => order.Total).ToList();

        foreach(var order in result)

        {

            log(result);

        }

    }

​

    public static void log(object o) { Console.WriteLine(o == null ? "null" : o.ToString()); }

}

​