Problem
Write a program called calculator that inherits from class average and also has methods that has: two methods multiply() to calculate the product of the numbers. One method will have two parameters which are both ints. The second method has three parameters: two ints and a Double. Another method "Power" that finds the power of a number using methods. For example, if the user types in: 5 and 3, the program should print out 125. 3. And another method "Factorial" which finds the factorial of a number using methods. Create a tester class to test all methods. Ask for user input.