I took Compass in May 2013, for LPN school, it was reading and math. I am not sure if it's the same test for RN, but I’ll chime in here since there's not a lot of info here on AN, surprisingly.
They say there is no time limit... but they gotta close sometime! I went in at 11:30 after I ate lunch in my car in the parking lot so I wouldn't get hungry if it took five-six hours. I figured I'd be good. It took about an hour.
The reading was crazy easy. The essays which the test asks you about stayed on the computer screen the whole time! I'm beginning to wonder if that was a glitch that made me get an extra-high score! (got a 99 on reading) There were maybe sixteen questions about four essays. Took my time in a big way, re-read everything and caught one mistake I would have made if I hadn't. The test must be timed, though, or else I'd have gotten 100%, right?
The math was weird. There was one word problem which I could not figure out how it could possibly be solved. Then I started plugging in the multiple-choice answers and *duh* there was only one answer that could possibly be anywhere near right! I think there was NOT enough info, and they wanted to see if one was smart enough to do that!
There was a crazy fraction problem I haven't seen since elementary school (in NY so it was like a Tennessee high school problem, lol). I did it, wasn't sure about my answer, converted it all to decimals, re-did it and saw it was OK.
In total I think there were only five math problems, if that many. I got an 88 and I had to guess at one answer.
So I advise anyone concerned with the LPN compass to chill, plan to devote all day in case that's what it takes, and study your kids' algebra, fractions, and word problems.
Oh one other tidbit of advice: they put some smelly guy next to me and my allergies were causing me to need to blow my nose every few minutes; I wish for his sake as well as mine I had thought to tell the test proctor to please keep me far from others because I would not want to get anyone sick (then I would not have had to smell him).