This is a basic number-filtering exercise. To make the most of this exercise, look at only one story at a time, complete it, and move on to the next story. Try to do Test Driven Development (TDD) for this problem, if possible. If not TDD, at least write the test cases after writing the code - input and expected outputs are given in each story.
Story 1
Given a list of integers, write a program to return only the even numbers from this list.