A supplement to the Official Guide with 300 additional quantitative questions
The GMAT Official Guide Quantitative Review provides targeted preparation for the mathematical portion of the GMAT exam. Designed by the Graduate Management Admission Council, this guide contains 300 real GMAT questions from past exams including 45 never-before-seen questions, plus the following Don’t waste time practicing on fake GMAT questions. Optimize your study time with the GMAT Official Guide 2018 Quantitative Review using real questions from actual past exams.
Ironically, I finished this guide while being about two-thirds the way through an M.B.A. program. It's certainly a great text to help prepare for the GMAT, but not particularly useful once you're already in a program. The questions are primarily meant to be tricky, not hard, and are mostly concerned with money and time. The set of skills you are meant to acquire from studying for the GMAT are primarily concerned with accuracy and awareness.
Good luck to everyone working towards a future M.B.A.