This book is designed for students sitting for EdExcel exam. One important feature about this book is that it contains plentiful of revision exercises which were taken out from past exam paper of the same board EdExcel. I think this is the selling point of this book. Unfortunately, it is also the weakest point about this book in that there are many typo errors in both the questions and the answers. This is very bad when the pupil check his result with the answer, he will be totally confused if he has done the exercise correctly. In some cases, I dare say it is better not to check the answers at the back.
Statistically, there is a one in eight chance that you see misprints in either the questions or the answers. To substantiate my findings, I put down a few question numbers where you find printing mistakes, just from Review exercise one of book one: 3,18,28,40... Question 40 is really an embarrassing one: Both question and answer are wrongly printed. I guess the publishers did not do much proof reading before printing.
My conclusion is: Use it with care. Trust yourself if you think you got the right answer.