I'm Rebecca and I worked on the GMATPrep software. I can assure you that the practice exams included in GMATPrep do not draw from the practice questions so you can answer these without concerns. When you are ready you can then take your second practice exam.
If you've purchased the new questions pack, then you won't see the overlap between the practice questions and the tests.
However, If you have downloaded the gmatprep questions from this site, the you will see a huge overlap between prac questions and tests.
Hope that answers!
Fire the final bullet only when you are constantly hitting the Bull's eye, till then KEEP PRACTICING.
A WAY TO INCREASE FROM QUANT 35-40 TO 47 : a-way-to-increase-from-q35-40-to-q-138750.html
Q 47/48 To Q 50 + the-final-climb-quest-for-q-50-from-q47-129441.html#p1064367
Three good RC strategies three-different-strategies-for-attacking-rc-127287.html