"Gotcha" Questions

[allen.chan]

I'm about two weeks away from my exam and I've taken the mgmat CAT tests and recently took the two exams from GMATPrep this weekend. While I'm pretty pleased with my scores (760-780 range), I noticed that 90 - 100% of my mistakes on the quant section were careless mistakes where I forgot about an integer constraint, forgot about a positive / negative constraint or misinterpreted the problem in a slight way that led me to the wrong answer. Seems pretty silly to miss questions for these reasons.

1) Can one of the instructors provide any tips? (Timing obviously.. but feel like I'm pacing myself pretty well at 2 mins per question. Maybe I should tighten up on timing to give myself more time to thoroughly understand the question and note down constraints)

2) Is there a list of good "gotcha" questions where a side note or constraint is critical to the question? Want to study how the GMAT uses these to trick students. Thanks

[StaceyKoprince]

Pretty much, if they give you a detail on quant, it's because that detail is important in some way. So, first, write EVERYthing down. Everything.

Go through a bunch of problems and just write stuff down. Develop a consistent shorthand for yourself. When they tell me x is a positive integer, I always write x = pos int. When they tell me x is positive, I write x=+. You don't have to write things exactly the way I do, but you do need to do the same thing for the same piece of information every time.

The act of writing down "x=+" will automatically put that piece of info a little higher in the consciousness of your brain. You will also need to keep repeating to yourself what I told you up above: if they bother to give you a constraint, there's a reason. Until you've figured out what that reason is, you can't forget about that constraint.

Some constraints are more important than others. For instance, sometimes they tell me x does not equal zero, and then I notice that they use x on the bottom of a fraction. Okay, so they told me x isn't equal to zero because you can't have zero on the bottom of a fraction. Now I can forget about that constraint, and I didn't actually have to do anything with it. On other constraints, I will very much have to use the constraint actively.

So two mantras:
1) if they give me a constraint, it's important for the functioning of the problem; I can't ignore it till I figure out WHY they gave it to me
2) I write EVERYthing down, including all the little details / constraints (though I use shorthand - I don't want to transcribe the entire problem!)

Next, take a look at this article about how to minimize the mistakes that you make. (Note: you're always going to make some careless mistakes - don't expect to be perfect. But it is a good goal to try to minimize them as much as possible. :)

http://www.manhattangmat.com/articles/error-log.cfm