multiplicity number

    internal class Program
    {
        static void Main(string[] args)
        {
            Random random = new Random();
            int minValueNumberN = 10;
            int maxValueNumberN = 25;
            int startNumber = 50;
            int endNumber = 150;
            int numberN = random.Next(minValueNumberN, maxValueNumberN + 1);
            int result = 0;

            for (int i = startNumber; i <= endNumber; i += numberN)
            {
                if (i <= startNumber)
                {
                    result++;
                }
            }

            Console.WriteLine($"Количество чисел от {startNumber} до {endNumber} кратны {numberN}");
        }
    }
}