#region _Draw Detail
            // System.Windows.Forms.MessageBox.Show("page " + iPage);
            int yC = 120, xC = 60;
            int w = 100, h = 40;
            for (int i = 0; i < 6; i++)
            {
                int a = RandomNumberGenerator.GetInt32(1, 20);
                int b = a * RandomNumberGenerator.GetInt32(1, 20);
                int _e = RandomNumberGenerator.GetInt32(1, 20);
                int d = _e * b;
                int c = a * _e;
                if (rd_1.Checked)
                {
                    string _a = "", _b = "", _c = "", _d = "";
                    _a = a.ToString(); _b = b.ToString(); _c = "C"; _d = "100";
                    e.Graphics.DrawFraction(_a, _b, xC + 10, yC);
                    e.Graphics.DrawString(" = ", new Font("Angsana New", 20), new SolidBrush(Color.Black), xC + 110, yC + 15);
                    e.Graphics.DrawFraction(_c, _d, xC + 110, yC);
                }
                else
                {
                    if (RandomNumberGenerator.GetInt32(1, 1000) > 500)
                    {
                        e.Graphics.DrawString($"{a} คิดเป็นร้อยละเท่าใด\nของ {d}", new Font("Angsana New", 20), new SolidBrush(Color.Black), xC + 10, yC);
                    }
                    else
                    {
                        e.Graphics.DrawString($"ร้อยละ {a} ของ{d} \nเป็นเท่าใด", new Font("Angsana New", 20), new SolidBrush(Color.Black), xC + 10, yC);
                    }
                }
                
                e.Graphics.DrawLine(new Pen(Brushes.Black, 2), xC + 250, yC + 25, 700, yC + 25);
                e.Graphics.DrawLine(new Pen(Brushes.Black, 2), xC + 250, yC + 55, 700, yC + 55);
                e.Graphics.DrawLine(new Pen(Brushes.Black, 2), xC + 250, yC + 85, 700, yC + 85);
                e.Graphics.DrawLine(new Pen(Brushes.Black, 2), xC + 250, yC + 115, 700, yC + 115);
                yC += 150;
            }

            #endregion