The software does not have experimental questions.
Kevincan, can you elaborate on this?
Why would GMATPrep not have experimental questions or is GMAC trying to hide the algorithm?
gmatgonti - I hope you are not messing with us.
51, 47 is equivalent of 790 (out of 800 possible) - not sure who in their sane life could get a score like that right off the bat - can you post your photo?
The official test has 20-30% of experimental questions that will not count, but I would never base your score based on the number of questions you miss since that score will be very different if those are questions in the beginning/middle/end or if they are experimental. Your score is fantastic the way it is.
Founder of GMAT Club
Just starting out with GMAT? Start here... | Want to know your GMAT Score? Try GMAT Score Estimator
Need GMAT Book Recommendations? Best GMAT Books
Co-author of the GMAT Club tests
Have a blog? Feature it on GMAT Club!
GMAT Club Premium Membership - big benefits and savings