MCAT is unfamiliar to us in Britain: it stands for the Medical Colleges' Admission Test which wannabe doctors take throughout the US and Canada. It is obviously a very competitive test and sets high standards. The book models itself on the test. It contains about 36 passages with 5-9 questions on each. It is suitable for people preparing to enter difficult professions, not just medical school. I used it to tutor someone for pilot recruitment tests. He passed.
We both searched bookshops and the web for challenging material. It is difficult to find suitable material at this high level. I recommend this book for that reason, though I do have some reservations. The presentation is unattractive: grey, cheap paper, with small print. Even worse, there are some errors such as answers being wrongly numbered, and some answers being wrong ,by my reasoning. (By the way, my copy has 137 pages not 256 as stated.)
I still recommend it because it is useful and at a good standard.