Probability
# Introduction to Recursion

Which of the following is demonstrated by the diagram above:

Using 1'' x 2'' dominoes, there's one way to tile a 1'' x 2'' area, 2 ways to tile a 2'' x 2'' area, and 3 ways to tile a 3'' x 2'' area.

How many ways are there to tile a 4'' x 2'' area?

Bombus the BumbleBee wants to get to the cell containing honey.

Each time, he can only take a step to a neighboring cell, that moves him to the right.

How many ways does he have of reaching the honey in the last cell?

$n \times n$ square with $n \geq 2$ ?

Which of the following expresses the correct formula for the number of unit squares with exactly 1 red side in an