I don’t mean to be a pain in the sphincter (as Monty Python’s Icelandic honey merchant would say), but I believe the variables and what they represent could be explained better here.
What’s implied but not explained is that f and t represent the number of pickups of each type, not one pickup or one coin as he says in the video, or the value of the coins. This may be obvious to many, but I had to think a couple of minutes to figure it out, and it might be easy to miss for some and end up generating confusion.
So then when Gary says 5f + 3t, this means (number of pickups) x their value.
Perhaps this won’t be useful but just in case