using System;

using System;

using System.Collections.Generic;

using System.Linq;  

   public class Test {

        public string Cat { get; set; }

        public int Type { get; set; }

        public int Count { get; set; }

    }

public class Program

{

    public static void Main()

    {

            List<Test> myList = new List<Test>();

            myList.Add(new Test() { Cat = "A",Type =  1,  Count=  10 });

            myList.Add(new Test() { Cat = "B", Type = 1, Count =  15 });

            myList.Add(new Test() { Cat = "C", Type = 1, Count =  25 });

            myList.Add(new Test() { Cat = "D", Type = 1, Count =  5 });

            myList.Add(new Test() { Cat = "A", Type = 2, Count =  15 });

            myList.Add(new Test() { Cat = "C", Type = 2, Count =  30 });

            myList.Add(new Test() { Cat = "D", Type = 2, Count =  20 });

            myList.Add(new Test() { Cat = "B", Type = 2, Count = 10 });

            var query = myList

                    .GroupBy(c => c.Cat)

                    .Select(g => new {

                        Cat = g.Key,

                        Type1Count = g.Where(a => a.Type == 1).Sum(c => c.Count),

                        Type2Count = g.Where(a => a.Type == 2).Sum(c => c.Count)

                    });

​

            foreach (var item in query)

            {

                Console.WriteLine(string.Format("Cat:{0}  Type1Count:{1}  Type2Count:{2}", item.Cat, item.Type1Count, item.Type2Count));

            }

    }

}