internal class Program
{
    static void Main(string[] args)
    {
        int rangeStart = 50;
        int rangeEnd = 150;
        int randMin = 10;
        int randMax = 26;
        int counter = 0;
        int baseNumber;
        int currentNumber;

        Random random = new Random();
        baseNumber = random.Next(randMin, randMax);
        currentNumber = baseNumber;

        while (currentNumber <= rangeEnd)
        {
            if (currentNumber >= rangeStart)
            {
                counter++;
            }

            currentNumber += baseNumber;
        }

        Console.WriteLine($"Количество чисел от {rangeStart} до {rangeEnd} (включая эти числа)," +
            $" которые кратны {baseNumber} ровняется - {counter}");
        Console.ReadKey();
    }
}