DO NOT USE ARCO. MY God, this is a huge mistake. I know my name says only 10+ posts but I've been an SDNer for YEARS with a different screen name. So trust me when I say ARCO is not reputable, not at all. The tests are not at all comparable to the real thing and do not in anyway predict how you will do. For MCAT practice materials you must stick with either Examkrackers (the best, seriously!), or the Kaplan big book you get in the stores or the Kaplan and Princeton materials you get only via the class. Do not use Arco, Barron's or any of those other prep companies' materials.