Sal works through the 155 data sufficiency questions in chapter 6 of the the 11th edition of the official GMAC GMAT Review (ISBN Number: 0-9765709-0-4 published in 2005)
Have you tried this resource? Help someone out by sharing your thoughts!
Sign up for weekly(ish) emails with new, affordable learning resources for you and your kids from Learnamic, spam-free every time! (See samples)
What grade levels would you like to receive learning resources for?