Hi All,
If it's possible that ANY of these questions are from the 6 Official GMAC CATs, then I would suggest that you NOT work through this document until you've taken those 6 CATs first.
Seeing even a handful of 'repeat' questions on a CAT (re: questions that you've already tried to solve and/or already know the answers to) can significantly 'throw off' the Scoring Algorithm as well as your pacing, energy levels, fatigue, stress, etc. Your goal when taking a CAT is to receive a realistic score result - so that you can get a sense of your current ability level and what you would need to work on to improve. However, if your CAT score is 'inflated' (from seeing a few repeat questions) then you'll ultimately end up with a Score result that doesn't mean much and can actually hurt your studies.
GMAT assassins aren't born, they're made,
Rich