I just did a GMAT prep practice test and did terrible on math (or so i thought) - got 15 wrong out of 37. But my scaled score was 48, i was wondering if that is unusual ?
Also, I thought the questions on the test were much tougher than the ones in OG. What would be the best way to practice harder questions? I have the Kaplan premier edition, should I use that for math ? (I have heard the questions in it are tougher than the OG)

Thanks!
-PG