using System;

using System.Threading;

using System.Threading.Tasks;

using System.Linq;

public class Program

{

    public static void Main()

        {

            var longRunningTasks = Enumerable

                .Range(1, 5)

                .Select(_ => (Func<Task>)(() => Task.Delay(TimeSpan.FromMilliseconds(100))))

                .ToList();

​

​

            var index = 0;

            foreach (var longRunningTask in longRunningTasks)

            {

                Task.Run(async () => await longRunningTask());

                Console.WriteLine($"Task {++index} started");

            }

​

            Console.WriteLine("All Tasks started");

​

            longRunningTasks = Enumerable

                .Range(1, 5)

                .Select(_ => (Func<Task>)(() => Task.Delay(TimeSpan.FromMilliseconds(100))))

                .ToList();

​

            index = 0;

            foreach (var longRunningTask in longRunningTasks)

            {

                longRunningTask();

                Console.WriteLine($"Task {++index} started");

            }

​

            Console.WriteLine("All Tasks started");

​

            longRunningTasks = Enumerable

                .Range(1, 5)

                .Select(_ => (Func<Task>)(() => Task.Delay(TimeSpan.FromMilliseconds(100))))

                .ToList();

​

            index = 0;

            foreach (var longRunningTask in longRunningTasks)

            {

                _ = longRunningTask();

                Console.WriteLine($"Task {++index} started");

            }

​

            Console.WriteLine("All Tasks started");

        }

}