BTDT. It has been a while, but I think I got in the 400s without major studying and math is NOT my strong suit. It took until I moved to stop getting recruiting mail from a number of well regarded business schools. (I never did go though.)
Unless the scoring system has changed in the last 15 years, it is better to leave an answer blank than to make a wild guess. A blank is -.25 while a wrong is -1. Also, you get points if your name and information are correctly filled out – so be neat there as well.
Hatzlacha Rabba!