KöMaL 2006 B3913

Consider the following two number sets: $A=\left\{ \frac{3n-4}{5n-3}\colon n \in \mathbb{Z}\right\} \text{and} B=\left\{ \frac{4k-3}{7k-6}\colon k\in \mathbb{Z}\right\}.$ How many elements are there in the set $A \cap B$?