You get 12 pre-released questions (6 practical and 6 theory). In the exam, you will get 1 practical and 1 theory (selected by random). They question will be exactly the same as what is in the pre-released question (no number changes).
I never liked the idea of a pre-released exam. It is as simple as working out the answers beforehand and then just regurgitating the answer when you do it.