For this lab, you need to demonstrate basic use of functions in Java. Write code that includes the following:

$1.$ Function definitions. Include at least three functions with different parameters and return types.

$2.$ Function overloading. We have covered this concept in class without naming it$.$ Search for it and include code that demonstrates the concept.

$3.$ This final part is good mental exercise. Try your best to complete this task on your own. Submit whatever solution you come up with. Your score will not be deducted even if you get it wrong.

Consider the following statement:

If we list all the natural numbers below X$=10$ that are multiples of $3$ OR $5,$ we get the following numbers: $3,5,6$ and $9.$ The sum of all of these numbers is $3+5+6+9=23$

Write a function that takes in a number X and calculates the sum of the multiples of $3$ OR $5$ below X$.$ For example, f$(10)$ should return $23$ and f$(12)$ should return $33($since $3+5+6+9+10=33).$