monikakumar - For the Quant section,
GMAT Club Test Center is the best option. The questions available in the
GMAT Club Tests are fairly representative of the ones on actual GMAT. The questions are designed to closely represent the ones in the actual GMAT and are available at various difficulty levels. If you do not have access to the
GMAT Club Tests, please purchase the tests as early as possible. You'd see tremendous improvements in your Quant score in a few days to weeks. Also, you would find detailed answer explanations and forum discussions.
No denying that the quant questions in
GMAT Club Test Center are very similar to the ones on GMAT Prep and the real-GMAT but, for few test-takers, attempting full-length Quant Section tests do not improve timing; instead, you should take short quizzes consisting of 5 to 10 questions over 2-3 weeks time. When you take those quizzes, please try to complete individual questions within 2 min. Most importantly, you must actively review the solution post every quiz attempt. I'm confident you'll make significant gains over 2 to 3 weeks if you practice in an above-mentioned manner.