Hi Fredrick,
Unfortunately GMAT paper tests are copy right materials and for that reason they cannot be used on these forums. I understand that your test is near so this doesn't help you. However, I do have a few suggestions:
Try and search for the specific issue that you think you have problems with. For example, check this post:
post49525.html?hilit=twice%20as%20much%20vs%20double#p49525In the MGMAT SC guide, at the end of each chapter, there is a list of OG questions corresponding to the topic of the chapter. Use the ones at the end of "Comparisons" and "Parallelism" chapter to see which ones you had problems with. Try and search for those issues on these forums. Again, OG questions cannot be discussed for the same reason as before but there is a good chance that someone would have discussed the concept behind those questions
Regards
Sunil