I can't help but think his examples are symbolic manipulation and not actual mathematics.
These maybe of interest to physicists without access to a computer algebra system, but to actual mathematicians they are as meaningless today as being able to do your 12 times table in your head.
Not all of them mind you, the last 10 questions are still interesting, but again mainly to physicists.
Edit: which makes sense since he states the questions are a "mathematical minimum for a physics student", which is different to the minimum mathematics needed for a mathematics student.
Filters allow rather large families of wavelengths through. You don't have just red, you have a fraction of green. Because your eyes only have three types of photoreceptors they can be fooled by playing back a similarly large family of wavelengths back.
Slav surnames are gendered. * ski is male, * ska is female, * sko is neutral. Using gender neutral in this case is as insulting as calling him a dog.
Other cases where using gender neutral pronouns insults everyone speaking the language is using Latinx for Latino. If you want to butcher every other languages genders like they are in English, use Latin instead - the gender neutral form of Latino in English since only the middle ages.
We call the wind whistle-y past our whale-y ears "progress".