Hi g3lo,

When dealing with DS questions, it might be tempting to take a 'theory-based' approach, but you'll likely find it far more useful to TEST VALUES and assemble 'proof' of what options are available. DS questions 'test' a variety of different skills, including organization, accuracy, attention-to-detail, thoroughness, etc. If you only 'see' one possible outcome, but there is another, then you'll get the question wrong (and you won't even realize it). The 'math' required to answer most DS questions is relatively simple, so don't be afraid of putting the pen on the pad, asking "what if...", and writing down the possibilities.

GMAT assassins aren't born, they're made,
Rich