Верификация пароля на спецсимволы

Главное условие чтоб в пароле была как минимум одна цифра, буква, и спец.символ. Не знаю как можно сделать проверку этого:

    Random random = new Random();
    List<string> letters = new List<string> {"a","b","c","d","e","f","g","h","i","j","k",
    "l","m","n","o","p","q","r","s","t","u","v", "w","x","y","z","A","B","C","D","e","f",
    "G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
    List<int> numbers = new List<int> {0,1,2,3,4,5,6,7,8,9};
    List<string> specialSymbols = new List<string> {"!","@","#","№","$","%","^","&","*","-","_",
    "?","<",">"};
    List<string> newNumbers = numbers.Select(x => x.ToString()).ToList();
    var summaryList = letters.Concat(newNumbers).Concat(specialSymbols);
    IEnumerable<string> list = summaryList.OrderBy(x => random.Next()).Take(10);
    Console.Write("List<string> with letters: ");
    foreach (var element in letters)
    {
        Console.Write(element);
    }
    Console.Write("List<int> with numbers converted to string: ");
    foreach (var element in newNumbers)
    {
        Console.Write(element);
    }
    Console.WriteLine();
    Console.Write("List<string> with special symbols: ");
    foreach (var element in specialSymbols)
    {
        Console.Write(element);
    }
    Console.WriteLine();
    string password = "";
    Console.Write("Summary List<string> which contains 15 random characters for generating new password: ");
    foreach (var element in list)
    {
         password += element;
    }
    Console.Write(password);
    Console.ReadKey();

Прошу дать ответ попроще, желательно, поскольку я в этом деле еще зеленый джун. Спасибо)