Hi,
We have a total of 6 Computer Adaptive Tests, and we offer the first one for free. If you purchase the set of 6 or get access by purchasing a book, you will have a year's worth of access to all of the tests. While there are only 6 individual tests without repeated answers (the first of which you can get for free) you will have the option to reset your exams after the first six. Because the exams are computer adaptive, you'll be able to keep taking tests, and as long as your ability level continues to improve you probably won't see many questions repeated, at least not for the 7th and 8th. After that, you may begin to see more repetition.
You can find this information in the first point on this page:
https://www.manhattangmat.com/free-gmat.cfmQuote:
Full-Length Practice GMAT Test
Sample the exact form of a GMAT test. This practice test replicates the look and feel of a real GMAT. The Free Sample GMAT Test is the 1st of 6 Computer Adaptive Exams included with
Manhattan GMAT books and prep offerings.
Hope that clears it up for you!
Best,
Caitlin Clay