Anyone know what the difficulty of the Qs in the thread "Collection of GMAT Prep SC" are? I'm going through it right now and have completed 80 questions and am only getting 60% of the questions correct so far

. When I went through the OG, I was consistently getting 75-80% of the questions right and am wondering how I regressed so considerably. One variable could be that these questions are more difficult, but since the OG was a mix and this is probably a mix as well (given that it's taken from the software), I'm guessing that this simply isn't the case, but just wanted to double check. Other people in that thread were wondering about this as well, so if someone can help ALL of us out, that'd be great.
Also, I'm wondering how I can possibly improve my SC? I take my GMAT in 2 days and I'm not getting any better. I've gone through older
Kaplan,
Princeton Review, the OG, Manhattan Guides, watched Ron videos, and I'm still god awful at this. Can someone please suggest anything else I can do, because I'm starting to think that this GMAT I'm about to take is not going to go well at all.
Thanks!
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