using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

         var type = new List<int>() { 1, 2, 3, 4 };

         var classes = new List<Tov>()

         {

             new Tov(4, "Велосипед"),

             new Tov(1, "Автомобиль"),

             new Tov(2, "Катер"),

             new Tov(4, "Мопед"),

             new Tov(2, "Лодка"),

             new Tov(1, "Самосвал"),

             new Tov(4, "Самокат"),

             new Tov(2, "Корабль"),

         };

        var v = 

            from t in type

            join cl in classes

            on t equals cl.Id

            into mass

            select new { Type = t, Mass = mass };

​

        v.ToList().ForEach(t => Console.WriteLine("Key={0}, Count={1}", t.Type, t.Mass.Count()));

    }

    public class Tov

    {

        public Tov(int id, string val)

        {

            Id = id;

            Val = val;

        }

        public int Id

        {

            get; set;

        }

        public string Val

        {

            get; set;

        }

    }

}