Most difficult math on the computer-adaptive GRE?
November 19, 2009 9:56 AM   Subscribe

GRE 800Q scorers: What was the most difficult math you saw on the computer-adaptive GRE?

I took the computer-adaptive GRE a few years ago, but ran out of time before completing the quantitative section and thus canceled my scores. I must have been doing relatively well, though, because near the end I was seeing problem types and math topics that had not been covered in *any* of the GRE prep books I'd used. (I think perhaps the prep books are intended more for helping lower scorers do better than high scorers do perfect.)

I'm taking the GRE again in January, and would like to score perfector near-perfect on the quantitative section. For those of you who scored at or near 800 quantitative on the computer-adaptive GRE, what sort of problems were you seeing at the end?

Thanks!
posted by Jacqueline to Education (20 answers total) 7 users marked this as a favorite
 
The questions about Bayes' Rule probabilities from graph data freaked me out, I probably missed 2/3 of them. They're much harder to do in your head because you're counting subgroups and unions.
posted by gensubuser at 10:04 AM on November 19, 2009


I must have been doing relatively well, though, because near the end I was seeing problem types and math topics that had not been covered in *any* of the GRE prep books I'd used.

If so, then chances are that the section you were solving was the experimental section. When I took the GREs, I remember having a math section that was hard all of a sudden, and then after that having another math section and realizing during the test that the previous math section wasn't going to be scored.

(I think perhaps the prep books are intended more for helping lower scorers do better than high scorers do perfect.)

Have you used Barron's series of GRE books to study? Not to shill, but I've found that the Barron's will often overprepare you for questions as hard or harder than the actual GRE test.
posted by suedehead at 10:21 AM on November 19, 2009


I scored 800Q, 700V. Don't remember anything terribly difficult. Mostly algebra.

Recommendation: get the Princeton Review materials. They're the best in the business. I didn't use them myself--I just fooled around with the practice materials ETS sends you when you register--but if I were to pick a publisher, it'd be TPR without question.
posted by valkyryn at 10:29 AM on November 19, 2009


Seconding that you probably ran into the experimental section. GRE math should all be SAT-level.
posted by pravit at 10:44 AM on November 19, 2009


If so, then chances are that the section you were solving was the experimental section. When I took the GREs, I remember having a math section that was hard all of a sudden, and then after that having another math section and realizing during the test that the previous math section wasn't going to be scored.

This is exactly how it happened to me. It felt sort of like when a cop turns his lights on behind you, and then drives around you.

I didn't score a straight eight, but I got pretty close. The hardest questions I saw were also about Bayes' probabilities. I didn't study any stats at all, because I figured I wouldn't see it unless I was doing well enough that it didn't matter, but if you're trying to ace it, I'd take a long, hard look at some statistics.
posted by solipsophistocracy at 10:48 AM on November 19, 2009 [1 favorite]


Thirding the suggestion that you got an experimental section. I scored 790 quant and didn't even really notice the questions getting harder. Toughest part for me was figuring out areas of irregular quadrilaterals, but that's just 'cause I hate quadrilaterals.
posted by shaun uh at 10:49 AM on November 19, 2009


Response by poster: If I recall correctly I had only 1 quant section and thus it was not the experimental section. I knew about experimental sections and wouldn't have canceled my scores if I'd had 2 quant sections and the second went better.
posted by Jacqueline at 10:58 AM on November 19, 2009


I got 800 on the math, and I don't recall anything harder than algebra and a little probability (Bayes' is conditional probability, yes?). The questions did get more difficult towards the end but not out of the league of the practice books. I also had a math experimental section which I thought I utterly failed, until an easier math section came up which was the 'real' one I guess. I studied with a bog-standard Kaplan book (which I found to better than the Princeton Review for math review anyway). I think you might be right about the books helping lower scorers in terms of solving tips, but they did help me in that they gave me examples of the type of problems, and had a good review of formulas to memorize (I tend to be a 'from scratch' mathematician which takes too long on standardized tests).

I do think the 'hardness' of the sections varies from exam to exam however hard they try to keep them even. So they score the exams accordingly; giving the people who took the hard one a different scale, so one set of exam takers doesn't get buffaloed. (I learned this from a friend who works for the College Board).
posted by bluefly at 11:20 AM on November 19, 2009


My experimental section was clearly marked, actually - the computer let me use a crappy, built-in calculator and everything. 790Q. I feel like my actual peaked near the middle, but it was more of a 'time consuming' issue with calculating stuff from graphs (Things like calculating 18 % versus 7% of 3450) The other stuff that I found 'hardest' was geometry because my prep book didn't sufficiently cover it and it had been years since I had done such things.
posted by cobaltnine at 11:21 AM on November 19, 2009


It's been a good 6 years since I took the GREs, but the Quantitative part of it made me scratch my head. It contained literally no additional material beyond the math that I learned in high school! Got my 800 with ease. If you know algebra, geometry, and basic probability, then you're set.

It all just seemed strange to me, because the Verbal section definitely expects you to have a college-level knowledge of the language and represents a huge increase in difficulty over the SAT. The GRE-Q pretty much just checks that you didn't forget math since you took the SAT.
posted by explosion at 1:08 PM on November 19, 2009


I did not get remotely close to a 800 -- hmph -- but the subject most conspicuously missing from my test was statistics beyond a petty P(A + B) question or two. I figure that's the first thing to go when you start answering questions wrong.

In general I found the real test much more difficult than the prep questions I found from various sources (including the GRE proctor itself!), so I felt a little let down by my efforts.
posted by spamguy at 1:52 PM on November 19, 2009


Same experience as everyone else. Just algebra, geometry, some minor probability, and I think a little bit of trig. Nothing college-level (not even any calculus). Got an 800. This was 4-5 years ago.
posted by equalpants at 2:20 PM on November 19, 2009


I think I got an 800 (or maybe a 790?) and I remember being surprised when I got a couple of statistics questions. They were pretty basic statistics -- I think I only had to know what percentage was the equivalent of one standard deviation in a normal distribution -- but I hadn't known there was even a possibility of encountering statistics so it caught me off-guard.

This was in 2005, for the record.
posted by pluckemin at 3:13 PM on November 19, 2009


Response by poster: Now that I've read your answers I remember better what it was that surprised me a few years ago -- I think I encountered some statistics/probability questions (my prep books covered only arithmetic, algebra, and geometry) and some hard geometry questions (involving concepts not covered in the prep books). So I'll find some additional non-GRE resources to review those particular topics. Thanks!

@equalpants: Trig? Really?

Did anyone else encounter any trigonometry? If that's potentially the "end boss" of the GRE quant section, maybe I should review that too if I have time. Whee! What a fun winter break I have planned. :)
posted by Jacqueline at 4:03 PM on November 19, 2009


I got an 800 a couple years ago and had a similar freakout in the quant section the first time I took the test. This wasn't even towards the end of the test but at the beginning. I don't remember it testing me on anything totally different from the Princeton Review/Kaplan books etc. but I do remember thinking that it required me to combine concepts from different sections of those books in a way that those books don't really prepare you for. Logarithms and guessing numbers were involved somehow. Nothing earth-shattering, just unexpected. I wanted an 1600 so I freaked out and cancelled the test. I don't even know if it was experimental since I didn't complete the questions (stupid, I know, since I could have gotten some practice and cancelled at the end).
posted by peacheater at 4:04 PM on November 19, 2009


There was definitely trig, not particularly advanced trig but all the major types of right triangles etc.
posted by peacheater at 4:05 PM on November 19, 2009


I took the GREs about five years ago, got somewhere in the high 700's, and I definitely remember some trig questions, what you'd expect to know after taking a high school trig course. For me it didn't show up towards the end, but near the beginning, too.
posted by needled at 6:08 PM on November 19, 2009


All I recall beyond basic algebra were various geometry and probability/stats problems that took a bit long because I hadn't done anything with geometry in, oh, 10 years. Geometry included some of the stuff trig is based on - right angle triangles, etc. - but I don't recall any actual trig. If there was any, it was so easy it didn't really register, and there wasn't enough of it to affect scoring much.

For me, the worst part was the fact that - unlike every other standardized test ever - I couldn't go back and look over the section when I finished and correct dumbass mistakes. (Two dumbass mistakes that I realized were dumbass mistakes a few problems later were what hurt my score.) I highly recommend practicing using the pseudo-GRE software the ETS (and some of the prep companies) give you, so that you're comfortable with the format.
posted by ubersturm at 6:15 PM on November 19, 2009


Yeah, what peacheater and needled said re: trig. I don't think you had to know any of the fancier identities or anything (maybe just sin^2 + cos^2 = 1), but just basic stuff like sine and cosine of 30°, 60°, etc.
posted by equalpants at 6:16 PM on November 19, 2009


Yeah, as far as trig, you don't really need any info beyond the ratios for 45-45-90 and 30-60-90 triangles. There's certainly not going to be anything on there about sin, cos, tan, or inverse relationships.

I found the most difficult problems were the ones where they give you a chart or graph and you have to find percent increases, decreases, etc. The math wasn't difficult but the questions were very specific and the wrong answers evilly calibrated to simple mistakes. Read these questions over really carefully several times and make sure you're answering exactly what they want you to answer.

Also, keep in mind that you can miss a few questions and still get an 800. The most difficult question I had was on the volume of a cylinder with all sorts of exponents everywhere and I just couldn't figure it out. But I still got an 800, and I know I got another question wrong because I realized 15 seconds too late that I'd made stupid arithmetic errors.

No matter how difficult a problem looks, there's always a "trick" that you can use to solve it under 30 seconds. The way to get good at this is to take as many practice tests as you possibly can.
posted by venividivici at 4:12 AM on November 20, 2009


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