I agree with Hawk, Whilst doing the course should improve your ability to handle these questions and get more of them correct, it only really improves your chances against those of an equal calibre that haven't done any prep and are ill prepared for what they face.
If everyone does as the airlines suggest and practice, then you're not really increasing or maximising your chances as the airlines will still only take the top XX percentile.
I should imagine these days everyone is worldly wise and the majority of candidates practice, so any perspective candidate would be foolish not to just to ensure they are playing on a level playing field with their rivals.
Either way, I would practice so i am less stressed during the tests.
Kinda turns it all into a competition and I think that the fact airlines invite candidates to re-apply 12 months later int he hope they do better against the next batch of candidates kinda proves that!
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