Comprehensive Prep for GMAT Data Sufficiency. Every year, students pay $1,000 and more to test prep companies to prepare for the math section of the GMAT. Now you can get the same preparation in a book. Although data sufficiency problems are difficult, they are very learnable. GMAT Data Sufficiency Prep Course presents a thorough analysis of GMAT math and introduces numerous analytic techniques that will help you immensely, not only on the GMAT but in business school as well. Features: Comprehensive Review: Twenty-four chapters provide the most thorough review of data sufficiency math available. Practice: Includes 196 examples and more than 205 exercises! Performance: If your target is a 700+ score, this is the book!