Action if more than one post

Hi there.

I have a custom post type called “resources” and a taxonomy called “books”. I need a loop to preform an action IF there is only one post for the taxonomy and preform another action if there is more than one post.

So
Scenario A – IF – there is one post in the taxonomy books
Scenario B – ELSE – there is greater than one post in the taxonomy books.

If anyone has an idea that would be great!

Thanks!