by Rich Cohen, EMPOWERgmat Rich.C@empowergmat.com
This series of emails and PMs focuses on situations that many Test Takers face during their studies. The names of the original posters have been changed to protect their identities.
Thoroughness on DS Questions
Hey Rich,
I’m having trouble with DS.
Is x > y?
2) |y - x| = x - y
I chose to do algebra. Therefore we have y-x=x-y => 2y=2x =>x=y
1=1 2=2 3=3 and thus x is not greater than y when tested against the question stem. So the answer is should be B. But it is NOT B and I don’t understand why.
This is simply not fair. Different techniques give us different answers, How is this possible? If I was writing my test today I would answer it as B. How does one get questions like this right? One technique may give you a totally different answer..
Goram
Hi Goram,
In DS questions, you have to be a bit cynical of the given information. There will ALWAYS be at least one result that you can "figure out"; however, DS questions are built to test your THOROUGHNESS, so keep your eyes open for OTHER possibilities.
In this prompt, we're asked "Is X > Y?" This is a YES/NO question.
IF X is greater than Y, then the answer is YES
IF Y is greater than X, then the answer is NO
IF X is EQUAL to Y, then the answer is NO
You have to consider all of the possibilities. If you DON’T consider them, then you might have an incomplete answer. That does NOT mean that it’s a ‘different’ answer – it means that it’s an INCORRECT answer.
TESTing Values is a great way to work through the various possibilities (and to make sure that you don't "miss" anything). As it stands, TESTing Values works well on most DS questions (and many Problem Solving questions); here, you can TEST VALUES and prove that X > Y is a possibility and X=Y is a possibility.
‘Symbolism’ Questions on the GMAT
Rich,
Please help me understand the following question:
For a finite sequence of non zero numbers, the number of variations in sign is defined as the number of pairs of consecutive terms of sequence for which the product of two consecutive terms is negative. what is the number of variations in sign for the sequence 1,-3,2,5,-4,-6 ?
a. one
b. two
c. three
d. four
e. five
Harvey
Hi Harvey,
The GMAT Quant section usually includes at least one "symbolism" question that will either "make up" a math symbol (and ask you to perform a calculation with it) OR make up a math phrase/concept and ask you to use the concept to answer a question.
These questions are essentially about following instructions.
Here, we're asked to take the PRODUCT of TWO CONSECUTIVE terms. If the product is NEGATIVE, then we have a "variation." So, given the included sequence of numbers, how many "variations" are there? To get to the correct answer, you need to work through every pair of consecutive terms (and you would find 3 "variations" – 1 & -3, -3 & 2, and 5 & -4)
These types of questions can sometimes take a little time to solve, but are some of the easiest "math" questions on the exam.
Verbal Note-taking and Pacing
Dear Rich,
How frequently should notes be taken in the Verbal section? In my last mock, when I realized that I was getting tired or couldn't understand the question, I did not take notes. Also, what should be the average time to read a passage and take notes?
Imelda
Hi Imelda,
I take some type of notes on EVERY question, even on SCs. It's the only way to make sure that I'm focused on the "right things" and catching the specific information that I need to answer the questions.
For CR questions, you should expect to spend 2 minutes, on average, per question. Keep in mind that some questions take more time and some take less.
For RC questions, each company/instructor has its/his/her own Tactics, but we teach that you should expect to read at a reasonable pace with the goal of ‘engaging’ with the prompt. Obviously, a longer prompt takes more time and a shorter prompt takes less time, but you’d be amazed how little time it actually takes to read a prompt and take some basic notes. About half the time, your notes will be enough to answer the question; the other half of the time, you'll need to go back and "hunt" through the original passage to find what you need.
This will take some time to practice. Focus on your accuracy first; speed and pacing only matter once you know how to properly handle the questions.
GMAT assassins aren't born, they're made,
Rich
