using System.Collections.Generic;
public static void Main()
double[] numbers1 = { 2.0, 2.0, 2.1, 2.2, 2.3, 2.3, 2.4, 2.5 };
double[] numbers2 = { 2.2 };
IEnumerable<double> onlyInFirstSet = numbers1.Except(numbers2);
System.Console.WriteLine($"{nameof(onlyInFirstSet)} count: {onlyInFirstSet.Count()}");
IEnumerable<double> onlyInSecondSet = numbers2.Except(numbers1);
System.Console.WriteLine($"{nameof(onlyInSecondSet)} count: {onlyInSecondSet.Count()}");