Simple Calculator
Create a non-static class named 'SimpleCalculator' in its own file.  The
class should contain a single constructor and should perform addition and
multiplication of sets of two and three numbers of type double.  When the
following sample 'main' code is run, it should produce the exact output
shown below:

SAMPLE CALLING CODE:
    public static void main(String[] args)
    {
       SimpleCalculator calc = new SimpleCalculator();

       calc.add(3.5, 4.2);
       calc.add(2.45, 7.1, 3.6);

       System.out.println();

       calc.multiply(1.9, 8.4);
       calc.multiply(3.8, 2.57, 4.6);
    }

EXACT OUTPUT FROM ABOVE CODE:
    The sum of 3.5 and 4.2 is 7.70.
    The sum of 2.45 and 7.1 and 3.6 is 13.15.

    The product of 1.9 and 8.4 is 15.96.
    The product of 3.8 and 2.57 and 4.6 is 44.92.

You must use the 'printf' method to display all answers (sums and products)
rounded to exactly two decimal places.  (Do not change the manner in which
user-supplied numbers are displayed.)

The above sample calling code is merely an example.  Your 'SimpleCalculator'
class should be able to add and multiply ANY two-number and three-number
combinations.  Also, remember that the method 'main' and the keyword
'static' must not appear anywhere in the 'SimpleCalculator' class.


Advanced Option #1
To the 'SimpleCalculator' class, add two more public methods, named
'addUnlimited' and 'multiplyUnlimited', both of which allow an unlimited
number of arguments of type double.  These two new methods do not need to
display the arguments back to the user.  They do, of course, need to
display the calculated answers.  Note that you may complete the other
advanced options in addition to, or instead of, this option.

Advanced Option #2
To the 'SimpleCalculator' class, add two more public methods, named
'subtract' and 'divide'.  The 'subtract' method should take two
arguments (doubles) and display the result when the second number is
subtracted from the first number.  Display the result in the same
manner that the 'add' and 'multiply' methods display their results.
The 'divide' method should work in the same manner as the 'subtract'
method, except that the two numbers should be divided.  However,
if the second number is zero, then display a statement indicating
that a number cannot be divided by zero.  Note that you may complete
this advanced option in addition to, or instead of, either of the
other options.

Advanced Option #3
To the 'SimpleCalculator' class, add additional methods of your
choosing.  For example, you might add a 'power' method that takes
two integer arguments and then raises the first integer to the
power of the second (e.g., power(2, 5) displays 32).  Or, you might
add a method named 'squareRoot' which displays the square root of a
number.  These are just examples, and you should consider adding
other methods of your choosing.  For each method that you add, also
add code to the constructor that displays a message (whenever a
'SimpleCalculator' object is created) that tells the user what
methods are available in your calculator.  Be sure to include in
the message the required methods, as well as any additional methods
that you added for the above extra credit options.  Note that you
may complete this advanced option in addition to, or instead of,
any of the above options.