August 30, 2006

GMAT Sentence correction - 2 tips for effective learning

I received a bunch of e-mails asking for help with GMAT Sentence Correction. When I started preparation, I too ignored SC only to discover that it was my biggest weakness. I did a lot of catching up in 2 weeks.

The key to getting better at SC is practice - there is no substitution. If you are preparing for SC, keep in mind these things

  • You can certainly improve with some systematic practice
  • Do NOT rely on your basic knowledge of english to 'sniff' out mistakes. You have to understand the rules.
  • With some focused study and learning the typical SC 'corrections' that GMAT throws at you, you can substantially improve your score. But you must learn the rules and understsand how to identify mistakes in the paragraphs.
  • MGMAT SC and Princeton Review 2007 have good SC strategies. MGMAT SC is the best when it comes to teaching the concepts.
Now coming to practice itself, here is how I did it. (Click on image to see larger version)

The idea is this:

When you are solving a question, write down a,b,c,d,e with adequate space between them. As you tick off the answers, write down 'why' underneath them - using the standard terminologies. Don't write "this is weird", instead, write "pronoun reference error."

Once you do this repeatedly - identifying the type of problem, listing it, cross referencing the answer (both correct and wrong answers) - you will get better and better at it. I rapidly improved my score from low 60% to close to 90% within 2 weeks by using this style diligently. Maybe I'm suggesting complete common sense, but hey - I'm saying what I did.

You should also scan passages and catch errors as they occur. This will help you eliminate answer choices quickly.

August 29, 2006

GMAT Quant Strategies - 7 top traps to avoid

Minor updates. This page is quite widely read for GMAT quant strategies, so I thought a few little changes/additional links will help.

GMAT is important - no matter what your personal philosophy regarding it is. Here is my post written much later that talks about relevance of GMAT in management consulting

my detailed GMAT debrief, which also gets many hits, is here. It might help you as well. Also adding a  numerical ability / quantitative testing preparation resource that could be helpful for case interviews

Having difficulty with GMAT Quant? Here are some of my tips and strategies that'll help you what to watch out for, and be ready for GMAT traps. Just like how many test prep companies give names to different strategies/methods/approaches etc - I've done the same, this should make it simpler.

The original post is available here - and for some reason if you can't access it, here is the reproduced text as of 28 Aug.

GMAT Quant strategies

Here are a few strategies that helped me (they were borne out of many tips the members here have given over a period of time). Math whizzes may not find them helpful, for people like us - who go from low 600s to 700s might find them useful. Like how these prep companies give names to specific strategies, I too have given each technique/trap a name so you can identify them. Hopefully some people will find this helpful.

Some generic Quant points

1. It is possible, even with 9-11 mistakes, to get 48-49 in Quant. So don't freak out because you think you got 3 questions wrong. The test is adaptive - i.e. every question does not carry equal weight. It does appear, however, that early questions do determine how your test will progress.

2. I've noticed, through my multiple GMATPrep tests, that even if you get more wrong in the end, you can still maintain a high score.

3. To go from Q(49) to Q(50) or Q(51) is going to be hard - if you have time constraints for studying (like I did), and you aren't a math whiz (which I'm not), then you need to understand what your trade-offs are - i.e. what topics you are willing to relax on and guess in the test. I basically studied enough to solve simple problems in permutations and combinations, and told myself - "if it looks hard and I can't think of a way to solve it in 30seconds, I'm going to use my 'good-looking-number' strategy (which I'll cover here) and just move on.

4. If you spend over 4 minutes on a question, you certainly are excited about digging your own grave, or you're probably an adrenalin junkie who loves to jump off a cliff without a parachute.

5. With practice, you'll realize that the real time saver in Quant is actually DS and not PS.

GMAT Quant

Is not actually very hard in itself, but when you combine the time pressure, the tricks in the question and the wording - it becomes very important that you have practiced many standard questions types, many times over - because when you see a question, you don't want to be thinking "hmmm...which of my 34 cool strategies might work for this?", you want to be going straight into solving it.

7 Trap identifiers

Many GMAT questions have subtle traps in them - but thankfully, you can categorize many of them - they have a pattern. I've tried to identify 6 of them. So look out for these! At the end of the day, if even 1 of these helped you get 2 questions right bumping you from 660 to 680, it's still good, right?

Each strategy/trap identifier is not a stand-alone, a GMATQuestion might require you to employ more than one at a time. They are listed in no particular order of importance.

These tips can help if you are forced to guess, but want to make an intelligent guess, or if you want to shorten your path to solution (or salvation)

1. The Lone Wolf

A lone wolf question almost always has a free standing number(or numbers), and a more complex looking equation as the other option. For e.g.

"On a loan, evil necromonger charges X% interest in the first year, and Y% interest in the second. If he loaned Rhyme 20,000$ in 2006, how much Rhyme pay by interest in 2008?"

A) X = 10
B) (X + Y + XY/100) = 100

You can almost be certain, that in such questions, your equations to the stem will reduce to a form that looks like (B), so (A) is actually redundant. Be careful of lone wolves because they will bite you in the posterior if you choose (C).

If you notice a lone wolf question, and you have no clue on how to solve the problem, choose (B) (or whichever is the complex equation).

*as a side note, a wolf, contrary to the popular belief, is a very social mammal and is not at all a loner.

2. The Spy Girl

In a typical movie, an unsuspecting man may be enchanted by a hot looking woman, who comes on to him easily. He sleeps with her only to be stabbed in the moring, and all his nuclear secrets stolen. That's what a spy girl question does - it looks real simple, and if you fall for it - you've had it.

Consider this

if the membership of the drama club and music club are combined, what % of the combined membership will be male?

(1) of the 16 members of the drama club 15 are male
(2) of the 20 members of the music club, 10 are male

On the outset, it's very simple. (C) should tell us, right? wrong! DS is picky. This is an overlapping sets question, so you need to consider if some belong to both clubs - and that would lead to (E).

When you get spy girl questions, take a few seconds to re-read the question, looking for holes and any tricky stem ends. Many GMAT sentence tricks are at the end of the question stem. Spy girl questions are often in DS, and typically masquerade as word translations.

3. Twin trouble
Some DS questions have 2 choices that both reduce to the same form! When you see 2 similar looking/structurally similar answer choices, quickly scan them to see if they reduce to a common form. For e.g.

"Question: blah blah blah..."
A) 2x+3y = 10
B) 3.2x+4.8y = 16

Cool! 2 simultaneous equations with 2 unknowns - so should be (C), right? wrong. If you multiply (A) by 1.6, you get (B). They're useless. In general, twin trouble questions end up with (E) as the answer (E is the best choice if you do not know how to solve the problem. If you do know, then if either A or B works - then D would be the answer)

4. C of pain
GMAT questions love to put two choices that seem to give a nice answer when combined. If you get (C) as the answer, unless you're absolutely sure of your approach, look closely at A or B again. Consider your equations to see if they can be solved with only A or B before confirming C. There are certainly more A, B, D choices in GMAT than C. If you are absolutely stumped by the question and you want to guess, this approach might help.

-if the 2 choices look very similar in structure, apply the 'twin trouble' tip - if it is a twin trouble, then E is the most likely answer. D comes next.

-if the choices look very different, go with the one that has a more complex looking wording or equation - and preferably does not allude to an addition.

-if you have absolutely no idea at all, and you must guess - choose D or E.

5. The Rambler
Ramblers are long worded, paragraph level questions. Ramblers have lot of BS in them - so scan the question, then come back to writing equations. Ramblers are not always hard - sometimes they're pretty simple distance/time questions (or work rate). Don't be intimidated by a rambler. For e.g.

"Jim ...blah blah..., he then stopped for 30 minutes to have lunch before proceeding..." simply means add 30mins to your time equation.

6. The Twister

Twisters are among the worst when it comes to tripping test takers (including me). They start innocuously, but what they ask for is subtly different from what your mind thinks you're being asked. Twisters occur usually at the end of a question in word translations, or at the beginning in number properties.

For e.g.
In 2006, Company X revenue grew 18% from 200,000$, company Y revenue grew 30% from 90,000$ - at the end of 2006, how much more would X earn than Y if X grew 20%"
If the question was a rambler, your mind would dim by the time you get to the end, and you'd furiously compute the new revenues, subtract the two and look at the answer. But wait, the X 18% is actually useless because the question twists in the end asking something else. Actual questions can be even more subtle than this - something like, instead of asking, "by how much did A exceed B", it might say "by how much did A exceed twice B"? Get the point? Read your question ends carefully.

In number properties, it's always good to map your mind to
-2, -1, -1/2, 0, 1/2, 1, 2 so you don't forget what you need to apply. Twisters occur at the beginning,

If it says number, instinctually many of us look at 1,2,3,4.. but "number" should immediately trigger -1, and -1/2,+1/2 in your sample sets. Always look carefully at the beginning (I know it sounds common sense, but common sense isn't always common...) and memorize the properties

number => -ve, + and - fractions, +ve, 0
+ve number => > 0, +ve fractions, and integers
integer => ...,-ve integer, 0, +ve integer
+ve integer => 1,2,...
-ve integer => -...,-2,-1,

It's common mistake to ignore zero in calculations, so be careful. For e.g.
if X not -ve and y is an integer less than -1/10, is xy to the left of 0 in the number line?

Well, if you consider 0 for X, then xy is on the 0 in number line...

7. The lucky twin (thanks to, and suggested by GMATT73)
The purpose of this problem is to exploit a weakness used by PVue: complimentary answer choices. Almost always in complimentary probability questions, there are a pair of "LUCKY TWINS" among the answer choices. If in doubt and pressed for time, choose a TWIN by logical deduction.

Let`s take a crack at this Project GMAT bad boy without making lengthy calculations.

Set S consists of numbers 2, 3, 6, 48, and 164. Number K is computed by multiplying one random number from set S by one of the first 10 non-negative integers, also selected at random. If Z=6^K, what is the probability that 678,463 is not a multiple of Z?

a. 10%
b. 25%
c. 50%
d. 90%
e. 100%


[added note by necromonger] - also watch out for complementary fractions and be careful. You might see numbers like
a) 1/2
b) 3/8

notice that 1-3/8 = 5/8 - these choices can trip you up if you haven't paid attention to the question carefully.

The good-looking-number (GLN) strategy
*Use this only when you are stumped in a PS question and you have no idea how to solve it, but you need to guess.

GLN's are simply numbers that are formed by some mathematical combination of numbers in the question. For e.g. if a rambler has number like '12.....3....9' and the choices are


what would you choose if you're in a real hurry? 4 = (12*3/9), the others-you can't get them by any straight manipulation. So 4 is a GLN.

GLN tips vary, their success rate is questionable. But in the absense of any clue, what have you got to lose?

closing points:
Don't be scare of quant. It is conquerable with some practice and employing some time-saving techniques. I'll be glad to answer any questions. Finally, choose the strategy that works for you - do not follow anything blindly because it worked for someone else!

finally, the obligatory:
*no animals were harmed in the making of these tips, and these strategies do not discriminate based on race, language, sex, creed, caste, tv viewing habits or choice of shirt colors.

August 27, 2006

GMAT Debrief / Experience - 740 with Q(49) V(41) AWA 6.0

update: March 2008 - since I wrote this post on my GMAT Debrief / GMAT Experience in Aug 2006, much has chanced. I went on to get into INSEAD, and I recently wrote this post on Consulting Recruitment and Relevance of GMAT score that you might find useful.

The beginning

I decided late May 2006 that I might want to consider going into business school, and I had to decide on taking GMAT. On June 1st, I decided that I should - and even checked my calendar and mentally decided that I would take the exam on August 26th. Since I had zero knowledge of gmat format and all other statistics related to preparation - I went to, did some reading, downloaded the software and took my first test (and I had no idea that it was actually adaptive). GMATPrep1 - got a 620, and I just quit the results screen without even bothering to see my Q and V. Stupid, I know.

In a day or two after that, I knew 620 wasn't good enough, and that 700+ was great. In any case, by first week of June, I was absolutely sure I would do GMAT.

The preparation

Without bothering to research much, I just went ahead and purchased OG 11 and Kaplan 2006-7 around 1st week of June, and once I received them, I began to work out the problems. Needless to say, I wasn't doing well. My Math was creaky, and while I thought I was good in verbal (because while I'm non-native English speaker, I've done all my education in English and am quite fluent in it), I realized very soon that I at it sucked big time. This realization, though, came rather late (as you will read later on).

My preparation was spotty - my job requires me to manage multiple projects and also be technically involved in some, so I would spend about 30-45 minutes a day at an average of about 4-5 days per week - and this continued through July. However, I did manage to spend time over weekends to at least take a full length test and analyse my weakness. In August, I did not prepare for a full week as I was out on business travel, but I kicked up a notch in the last 2 weeks with some intense preparation. My preparation style is a little unusual from most others, so be cautious what you take from it (I'll cover it in a little while)

Preparatory books
I used the usual culprits, OG, Kaplan, Princeton and MGMAT. Here is my preference list:

a) OG - you should do this to get a good feel of all sections. In my case, I actually did not finish DS or RC by the time I got to the test.
b)MGMAT SC - great book for SC, a must for non-native speakers.
c)Veritas math - for permutations and statistics. Great book but return-on-investment was 0 because I got no frikkin question on perm/comb
d)Princeton review - from my own experience - I actually liked this book! I really liked their sections on SC and RC, and their on-line tests weren't too bad either.

Preparatory software

a) GMATPrep is your bible, bhagavad-gita, Quran, Zend-avesta, star trek guide, latest edition of playboy - whatever is holy to you. Nothing even comes close to how close GMATPrep is to the real test - I'll cover this in more detail below because it's really important.
b)Princeton review tests - Good practice, they don't intimidate you by giving you idiotic scores (like Kaplan). The flip side is that their Quant correction is very unlike real GMAT - I got 47 by getting just 3 wrong, where in the real GMAT - only 3 wrong might give you 50 or 51.
c)MGMAT tests - again, very good practice especially for Quant.
d)Kaplan - dog crap. What more do you want to say?

The ETS paper tests should be used purely for questions practice, they are in no way representative of real GMAT. Don't try to analyze how you would do in GMAT by how you did in ETS paper tests. The Powerprep software is slightly better.

My preparation scores

I'll put up my full XLS sheet in a link soon - so I'll only summarize my performance here.

Kaplan CAT1 - 580 !@#$%#$
Kaplan CAT2 - 610 !@#$$!@#
Kaplan CAT3 - did not finish, got so infuriated and lost interest
Kaplan CAT4 - did not do.

In words of my good friend Eric Cartman - here's what I say to their material, "Scr--w you guys, I'm going home!"

MGMAT CAT1 - 620
MGMAT CAT2 and 3 - 680, 690. MGMAT is quite tough, so it's a good sign if you're hitting close to 700 there.
PR CAT1,CAT2,CAT3 - 680,690,690 (or maybe I got 710 in one..not sure)

GMATPrep - 700,710 ; 740,750 ; 770, 760; 770; Now you'll wonder if I was nuts doing it so many times, and I'll tell you you'll thank me why. And I did all these in the last 7 days.

As you can see, my scores improved over time - and I hovered close to 700 in MGMAT/PR and touched 700+ on GMATPrep.

My study strategy/style

*warning: My style was a little unusual compared to most. You can choose to use aspects of it, but you need to know what works best for you. My reasoning may not be the best one for you!*

1. I actually did not even finish OG completely, I focused more on basics and then analyzed answers from my tests. My reason? OG has questions that sometimes repeat in the prep software - it skews performance in the tests. I wanted my tests to be as accurate as possible. I read initial parts of OG, did most of SC, some CR, Q and DS (about 50-70%) by Aug last week and then went through the problems after I finished a couple of rounds of GMATPrep only learn techniques for harder areas.

2. I did not use any error log as such. Once I did a test, I looked at my statistical performance - where did I get hit the most? how many questions? This worked nicely for me. Instead of obsessing over every single type - I focused on a category. Here is how it actually worked for me.

Initially, I was hurting in Quant, specifically number theory. My geometry and algebra were strong and needed only brush up. So I focused on number theory and fair enough - scored improved. I targeted statistics next, and finally word translations. I knew I had no time or patience to master perm/comb - so I brushed the basics and left it at that. Attack what you can master, and understand what you are willing to trade-off on. Once I hit 48-49 on Quant, I went after verbal. My CR improved quickly after I read through some tips on PR, and then went after SC. Lots of practice (about 200 from 1000SC, all of OG, and great summaries in PR) and I got better. Not great, but better.

3. Here's the most important thing: I did GMATPrep about 8 times! Of which 6 were in the last 5 days. This is unusual but it really, really helped. Do not think that once you do the 2 tests, you should stop because questions might repeat. The great thing about GMATPrep is that Quant will get you fresh questions for most part while verbal will repeat in increasing amounts (RC will repeat a lot, but you can get newer SC questions). GMATPrep is really close to the real thing, and when I sat in the real test - it just felt so comfortable and familiar! I knew the type of traps they were laying out for me, I knew what to look out for, and what approach to take to many questions. Even if you take everything else I say to be a rant of a senile mind, please don't ignore this! I will post a separate note on some useful tips on GMAT quant.

Leading to the test/The test day
I slept late the 2nd day before the test, and woke up early the day before the test. This ensured I would sleep fitfully the day before the test. Thankfully, tests have never fazed me all my life (regardless of my level pf preparation ;) ) - they don't make me nervous so I was peaceful the day before. I did 2 GMATPrep tests, practised 50 SC - and in the evening visited my test center (which is was really useful because the directions were confusing and it took me time to find it). I slept fitfully because I was exhausted.

Test day - my test was at 12:15 but I thought I'll take a chance by going in early. Was there at 11 AM and voila, they said I could take it right then if I wanted to. Nice center, friendly staff. After ID verification (non-US citizens take your passport to the center) I was taken in to the center. The first thing I did was to test the writing pen, it wasn't writing! I got a replacement immediately, and here's another funny thing - I actually liked the writing pad and pen! Center was reasonably quiet - I did not use the ear plugs, they annoy me. Ambient noise was not an issue.

I had never practised with AWA, not once. Hey, I'm a manager, I write reams of pompous stuff all the time, 2 essays weren't going to fatigue me ;) I think I did a decent job at AWA. Nothing much to say here.

took a break of 5-6 minutes, and took a deep breath to face quant.

Question 1: Wham! darned question - type of which I had never done before. Spent 3 solution...clicked on a guess, but hesitated to confirm answer. My mind was racing, can't get the first question wrong! Took an alternate approach by using a sample value - great! it worked! Next question - number properties, got it right. Then geometry, not simple - I think I nailed it. I knew the questions were not simple - but I couldn't really make out if it was getting harder and harder. My only guess was that since questions were longer and needed me to think, they were probably in the harder sections. Lot of number properties - so please prepare for them. No question on Probability, and I don't think even a single question made me think "what the hell..?" My repeat GMATPreps really helped in feeling familiar. By the time I ended the quant with 30s to spare (I guessed the last-second question), I knew I had done decently.

break. 4 minutes, some water. No snacks. Back for verbal.

Q1: Pretty involved CR - had to think quite a lot before answering. Second question was a big underlined SC - big but not hard, choices were easy to decide on. I could never make out if verbal was getting harder or easier - I felt good all the way. Couple of SC's got me, but that was OK.

Test over with 20 seconds to spare, and the survey started. I felt peaceful, so I went through the questions without any irritation. Finally, "do you want to see your score" (do you want to see carmen electra in a bikini?) - I clicked yes and it took about 15-20 seconds for the result. Man it felt long. Finally, 740 flashed! I grinned all the way to the car and home :)

Now I can get to the next step with confidence. To summarize some key points

a) Study basics first, get your fundamentals clear in quant. Number theory is important.
b) SC will get you the best improvement in score in verbal
c) Very important to be calm and composed during the test. Get good sleep beforehand.
d) During the test, don't let a hard question faze you. If you cannot understand the question, take a call whether you can solve it or not. If you can't, guess and move on. Try to get the earlier questions correct. I'll write a separate post on some tips.
e)Practise using GMATPrep, a lot. The real test is very close to it.
f)Don't try to guess if a question is hard, experimental etc. etc while testing. Just focus on solving it and getting it right withing 2 minutes.
g)Spend time on this forum. If you got a a question wrong, search for threads here and understand the solution. This forum and its people are fantastic, for guidance, help and inspiration. I spent some amount of time every single day on this forum.

What I wish I had done better

Given that I got 740 - in hindsight, it might have helped if I practised SC a lot more, that might have got me 760.. and some more practise in mixture questions might have got me a 50 in Q. But once you cross the 730-740 mark, every 10 points requires a lot of preparation - so I think I should shut up and be happy at what I got. Sure I would have liked 770, but then I would have also liked to have Warren Buffet donate me a 100 million dollars, "ain't gonna happen."

(The original post is in , a fantastic forum with great people, whose help and advice was a significant factor for my preparations and result. You can read the post and responses here