using System;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        var min = -20;

        var max = 20;

        var randNum = new Random();

        var dataSource = Enumerable

            .Repeat(0, 20)

            .Select(i => randNum.Next(min, max))            

            .ToArray();

        var result = dataSource.Select(i => i > 0).ToArray();

        Console.WriteLine($"positive count: {result.Length}");

    }

}