Hello, I'm having some trouble with this math problem that I received.

Hello,

I'm having some trouble with this math problem that I received. I'm not entirely sure how to unpack the wording of the problem to get at what the problem is really asking of me, let alone where to start with it;

Let A be a set. Prove that A is finite if and only if there is an injective function f : A → {1,...,n} for some n ∈ N if and only if there is a surjective function f : {1,...,n} → A for some n ∈ N.

Thank you for your help.

All the best