Assignment:
Q1. How many different trains of white (1x1) and/or red (1x2) rods are there of a given length N? Find at least 2 ways to justify your solution.
Q2. Can you find an equation to express the number of trains of length N that can be formed using white, red and/or green (1x3) rods?
Provide complete and step by step solution for the question and show calculations and use formulas.