Let $p:Y\to X$ be a covering space and $p^{-1}(x)$ countable for every $x\in X$
Show, that if $X$ is second-countable, so is $Y$
Hello,
I am a little bit stuck with this question, because I do not really know, how to involve the fact, that $p$ is a covering space. Could you give me a hint on how to do this?
Thanks in advance