This is a set theory question regarding relative complement.
If $A = \{n \in \Bbb{N} : 5 \mid n\}$ and $B = \{n \in \Bbb{N} : 10 \mid n\}$. List all of the elements that are in $A \setminus B$.
Wouldn't this be asking to list an infinite number of multiples of $5$ that have the multiples of $10$ taken away from them? If not, then what is this question expecting an answer of?