Hi hassan233,
Most GMAT questions are written so that they can be approached in more than one way - so with any individual prompt, you have 2 goals (correctly answer the question AND do so in an efficient fashion). If you've noticed that you're taking a lot longer to answer certain questions that you ALSO get wrong, it's possible that these are tougher questions... but it's ALSO possible that you are approaching them in an inefficient way (that's costing you time and keeping you from getting the correct answer).
Before I can offer you the specific advice that you’re looking for, it would help if you could provide a bit more information on how you've been studying and your goals:
1) How long have you studied? How many hours do you typically study each week?
2) What study materials have you used so far? What “brands” of CATs/mocks have you used?
3) On what dates (or approximate dates) did you take EACH of your CATs/mocks and how did you score on EACH (including the Quant and Verbal Scaled Scores for EACH)?
4) When are you planning to apply to Business School and what Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich
760+: What GMAT Assassins Do to Score at the Highest Levels