It’s basically a more advanced version of the SAT or ACT - reading, analytical writing, and high school-level math. The reading is more advanced, the essay in and the analytical writing is also more advanced, which makes sense since the GMAT is meant for college graduates who intended to attend business school. The math is about the same difficulty as the SAT or ACT, since many GMAT takers haven’t taken much college-level math.
If you worked reasonably hard in college, and you review GMAT math (any review book will do, and hiring a tutor is better), you’ll do fine.
Author: John Linneball Who did you think? ;-)
I'm the proprietor and only tutor for this business; that's why I named it after me.