Hi there,
As others have said, there is no good way to answer this. Your score depends on the difficulty of the questions you see (harder questions count for more points), and when in the test you get your wrong answers (e.g., it's better to get a question wrong at the end than at the beginning).
That said, when you're doing your practice, if you want to score in the 700s you should be getting virtually all of the easy to medium level questions right, plus a pretty good portion (half?) of the difficult questions.
The best way to gauge yourself is to take an adaptive practice test - just doing problems out of a book won't give you a very accurate picture of your score range, even if it is is excellent practice!
Hope this helps!
Jim S. | GMAT Instructor | Veritas Prep
