Math class
9.
            Random rnd = new Random();
            double n1 = (double) rnd.Next(1, 7)/ rnd.Next(8, 15);
            double n2 = (double)rnd.Next(1, 7) / rnd.Next(8, 15);
            double n3 = (double)rnd.Next(1, 7) / rnd.Next(8, 15);
            Console.WriteLine((n1+n2+n3)/3);
12.
            double a = double.Parse(Console.ReadLine());
            double b = double.Parse(Console.ReadLine());
            double c = double.Parse(Console.ReadLine());
            double dtr = a + b + c;
            double p =  dtr / 2;
            double prm = ((p) * (p - a) * (p - b) * (p - c));
            double area = Math.Sqrt(prm);
            Console.WriteLine("Area of the triangle is: " + area);
            Console.WriteLine("Diameter of the triangle is: " + dtr);
13.
            double sumMoney = double.Parse(Console.ReadLine());
            int cents = (int)(sumMoney * 100) % 100;
            int nis = (int)sumMoney;
            Console.WriteLine("the sum in nis is: " + nis + " nis and " + cents + " 			cents");
15.
            double gradeA, brk;
            gradeA = double.Parse(Console.ReadLine());
            brk = gradeA - Math.Round(gradeA);
            Console.WriteLine(gradeA + " broken " + brk);