public class Finance
{
  public static double interest(int years, double start, double rate)
  {
    return start * Math.pow(1 + rate / 100.0, years);
  }

  public static double payment(int years, double start, double rate)
  {
    return start * (rate/100.0)/(1.0 - Math.pow(1 + rate/100.0, -years));
  }

  public static void main(String [] args)
  {
    // test the interest method.
    System.out.printf("Test the interest() method.\n");
    for (int i = 1; i <= 20; ++i)
    {
      double money = interest(i, 1000, 5);
      System.out.printf("%.2f\n", money);
    }

    // test the payment method.
    System.out.printf("Test the payment method.\n");
    for (int amount = 50000; amount < 500000; amount += 50000)
    {
      double pmt = payment(30, amount, 5);
      System.out.printf("%.2f\n", pmt);
    }
  }
}