Hello,
niceguyvin. First of all, let me congratulate you on a very high entry point on your first official practice test. Provided you have not seen the questions before and took the test under relatively realistic conditions, that is an excellent score. Many people who eventually push into the 700s, especially those who work on a shorter prep schedule, start in the 600s. I agree with what has been written above. No, the in-house grammar book is not enough to get you to where you want to be regarding SC questions. In fact, some of the exercises contain debatable answers in the name of making a particular point, and that can actually prove a hindrance to your understanding and your approach to questions. (I am not saying it is a terrible resource, just that it has flaws; to someone looking at it for guidance, it may prove troublesome in parts.) If you want to pursue the cheapest way to learn Verbal strategy, read the Ultimate Beginners' Guides series by
GMATNinja (found in the signature of any post by Charles); when you go through OG questions, look them up in the forum and read through the community dialogue, particularly the responses of Experts, and take notes on what could help you improve your own approach; practice official questions by choosing certain tags in the
Question Index on this site. Do not rush. Take your time to understand how the question is put together so that you can better unravel it or one like it. You will notice a rapid progression at first. Once you hit a plateau, that is the point at which you can seek further guidance, especially after you have more data in hand from another practice test.
To be clear, I am
not making the above suggestions in lieu of what others have written; rather, I am complementing them by pointing you to other (even cheaper) resources, those that I consider to be top notch.
Good luck with your studies.
- Andrew