I have found a plethora of errors due to lack of attention to detail. Oftentimes the question asked and the "correct" contradict themselves or the explanation for the answer skips over steps entirely jumping from point A to point C.
The reading for each chapter is very generalized info and doesn't actually explain how to solve certain problems. I recognize that it's supposed to be a supplemental study tool, but considering it was written by the same people who wrote the test you'd think information would be more accurate and helpful.