I don't want the full solution rather a step in the right direction. I believe what I have so far is right but I just would like to verify and know the final basic steps to find out how many ways the experiment can be performed. Here's the question:

I don't want the full solution rather a step in the right direction. I believe what I have so far is right but I just would like to verify and know the final basic steps to find out how many ways the experiment can be performed. Here's the question:

Think of it from the beer's perspective. Going down the line, what can happen to each beer?