I am currently using Geffner's new 5th Edition, c. April 2010, and unfortunately many of the answers in the back of the book are incorrect. This is adding confusion to my studies and my quiz scores are lower than they could be. I am currently an online student and study by myself. I was hoping a prior edition of the book would contain the correct answers (at that time), but I see a reviewer of the 4th Edition has complained about the same problem. It is too bad because the order and contents of this book are very good. I have emailed the publisher asking for a corrected answer section but have not heard back at this time.