I think this is a basic question, but I am not very knowledgeable about the topic.
I am trying to understand this answer to a question of mine.
I know from this answer that the number of hyperplanes in a vector space over a finite field $\mathbb{F}_q^n$ should be $q^{n - k}{n \brack k}_q = q (q + 1) (q^2 + 1)$ for $n = 4$ and $k = 3$ in my case.
But in $\mathbb{F}_q^n$, in particular for $n=4$, how many points lie on a hyperplane?