if your only doing chapters 2,3,4 you could have bought the chapters from ebay for about 99p.. and you didnt need to register and pay, there are many free sites out there, eps good is the one i mentioned earlier, both my stepson and my wife just read the pdf file i bought off ebay and i printed the questions and the summaries off the web site i mentioned b4, and they both passed first time.
but dont take it for granted it easy, in the group my wife and stepson was in, only about 3 out of 10 passed. so study well