The scoring is calculated using a very complicated algorithm, so there isn't a set answer to the question "what's the penalty for not finishing." As a very general rule, leaving questions blank can result in a penalty of up to 3 percentile points per question, but this varies based on various parameters (scoring level, number of questions, etc.).
Let's just say: it did hurt your score, probably quite a bit. The pain wouldn't have been limited to any blank questions. You also presumably noticed that you were running behind and starting rushing to try to catch up, which would have caused a lot of errors on questions that you might have been able to answer had you been able to work under normal timing conditions.
That's actually good news. I know that sounds strange, but the good news is that we know what went wrong. If we know what went wrong, then we know what we need to do to fix it. :)
I worked out OG questions but didn't review them. And when I took the test, almost all the questions, especially in Quant, seemed new to me. Never did I come across those types while practising OG quant problems.
Oh, but you did. You just didn't recognize them. Want to know why?
didn't review them
Here's how you review test questions:
http://www.manhattangmat.com/articles/a ... roblem.cfmIf you haven't done that, you haven't actually learned how to recognize different problems of the same general type in future. It won't be as easy as seeing the same problem with different numbers tossed in. (I wish it were that easy!)
Next, the test is changing in June - they will be adding a new section called "Integrated Reasoning." If you wait until August to take the test, then you will also have to prepare for this new IR section. (You'll only have to write one of the two essays, though.)
So you're going to have to decide whether you want to try to prepare to take it before 5 June or whether you also want to prepare for the next section. If you want to take it before, then you may want to look into joining a class, as that will help you to be more efficient with your study. You may also be able to do it on your own during that time, of course.
Take a look at this article:
http://www.manhattangmat.com/blog/index ... -the-gmat/It links to a bunch of other articles as well - follow them and read them all. That will give you a good idea of what you need to do, and maybe also help you to decide whether you want to take a class and have the help of a teacher in doing all of these things!