Princeton Review free CAT accuracy?

Hello AJ85,

Yeah that is surprising that it drops the score so much for one additional missed problem. The algorithm they use doesn't seem very good.

Today I was reviewing the questions I missed and one of them appears to be incorrect in their system! I am certain I got it right and it says I got it wrong. It is an easy question too!

Here is the question and tell me if I am right on this:

For all integers a and b, the operation # is defined as a # b = (–a + b)(b + a). If a = 2 and b = 5, then b # a =

–25
–21
–7
21
25

I marked D 21 as the correct answer, but it says the correct answer is B: -21.


Anyway, from what I have heard, the MGMAT CAT's are pretty accurate in their scoring. If you are getting around 710-730 you will probably get around there on the real thing. Have you taken either of the GMAT prep tests yet?

Good luck with your test.

In my experience, the Princeton Review CATs have been somewhat inaccurate. From what I have read, they focus HEAVILY on the first 10 questions of each section. This jives with what I was taught in my Princeton Review Classroom course, where they emphasized that, essentially, the only questions that really matter are the first 10.

This couldn't be farther from the truth, as anyone who has taken the real GMAT will tell you. Go back and look at your results from the PR CAT. You will probably see that you got 1-2 wrong in the first 10 of the math portion. By doing so, you basically guarantee that you can't recover and score >700. I have taken multiple PR GMAT CATs (scores listed below in my sig), and usually missed 5-10 math questions. Conversely, on my MGMAT and GMATPrep CATs, I have missed as many as 16 on math and scored in the mid 700s overall.

I would recommend using the Princeton CATs just for practice with pacing and timing. And yes, the math on PR CATs is a joke. Just take a MGMAT CAT and you'll get your socks knocked off (but still actually score well because their scoring algorithim is much more realistic). Ultimately, the GMATPrep CATs are said to be the best predictors of your score, as they are the ones actually made by the GMAC itself.

Hmm very interesting, thank you for the information. Yes, looking at the test report I missed the 2nd question due to a stupid multiplication error. I guess this is what really threw my score off.

In total I missed questions 2, 11, 12, 15, 29, 35, and 36. However, by my estimation there is an error in the answer key because number 15 I am certain I got right, but it is marked as incorrect. You can see the question in my post above.

Thanks again for the information. I haven't taken a GMATprep test yet, I am saving them for a little later. I guess I'll have to wait until that point to see where I am really at.

rjdunn03

The correct answer to that question is minus 21 itself. It's a tricky question, the basic function of a#b is (-a + b)(a +b) irrespective of what name you assign. in next step b and a is reversed, but in B#A you have to take (-b + a)(a+b) as b is assigned the function of A. so it will be (- 5+2) (5+2) = -21

Thanks for kind words regarding effectiveness of manhattan cats. Yes today I gave gmat prep 1. Got q49 v40 which corresponds to about 720. Got previously unknown questions on all sections except cr . Some of the crs I got I had seen before on forums. I think princeton skews the scoring because of easier questions it offers. However it's verbal section is not that easy so not a good algorithm at all.

Oh now I feel sheepish. I read it wrong, I thought I was finding a#b. Thanks for clearing that up for me.

Yeah I think the algorithm is poor, and considering the questions don't seem to be representative of the real test I'm not going to stress much about it.

Good job on the GMATprep test. Good luck with the GMAT, let us know how you do.

I just got 680 on PR free ( Q51 with 3 wrong, V33 with 11 wrong)

First sub 700 of the season...yuk....depressing

surely not going to give any more Princeton