using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

         List<string> timeList = new List<string>();

            timeList.Add("0:15");

            timeList.Add("2:00");

            timeList.Add("1:00");

            timeList.Add("2:15");

            timeList.Add("3:15");

            timeList.Add("4:00");

​

           TimeSpan totalTime = new TimeSpan(0, (int)timeList.Sum(x => getMinutes(x)), 0);

        Console.WriteLine(totalTime.ToString());

    }

     public static double getMinutes(string timeIn)

        {

            string[] components = timeIn.Split(':');

            TimeSpan ts = new TimeSpan(int.Parse(components[0]), int.Parse(components[1]), 0);

            return ts.TotalMinutes;

        }

}