CR(Critical Reasoning) is my favorite sub-section on the GMAT. Firstly, because I had 100% accuracy on CR. But more importantly,  I got to dissect a well formed argument.

You don't have to read loooooong passages and neither do you have to correct sentences. Some say, you can't prepare or practice for CR, but that's not true. Although, you do get diminishing returns after a point. So just practice until you have your techniques mastered.

Strengthen/Weaken type questions are fairly common. And so it is imperative that we know how to solve these questions correctly, with 100% accuracy. Let us see how we can achieve that level of accuracy on such questions:

The key is Identifying Assumptions.

Facts/Premises + Assumptions = Conclusion(s)

If you can identify the assumptions, you can make an argument stronger or weaker. Most people try to "Prove" that the conclusion is some how wrong, which is the wrong approach. Conclusions are never drawn wrong. They are based on facts/premises and assumptions.

So obviously, either the facts are wrong or the assumptions are wrong. Unlike certain news channels, the GMAT test makers never get facts or premises wrong. You cannot attack the facts given in a GMAT argument! Remember that!

What is left for us to attack then? Assumptions.

Assumptions can either be strengthened or weakened.

How? You ask.

By providing additional information that either supports or negates the assumption.

That's it. That's the key. All GMAT CR Strengthen/Weaken questions rely on you identifying the assumptions correctly. Once you identify the assumptions, all you have to do is go through the answer choices to strengthen or weaken the argument.

ONLY one choice will do the trick. Others will either do the opposite or will not have any bearing on the argument at all! So, use your superpower of elimination to cut through the noise and find the correct answer choice.

If you practice this with 30 questions, you won't get another S/W question wrong.

Everything revolves around the return on investment. Ultimately, schools either can or cannot keep up with the trends. MBA programs have been evolving continuously for the past many years, but for some reason a specific crowd of applicants no longer sees 2 year MBA programs as viable.

To know more about how MBA programs are at crossroads, you can read this book: Rethinking the MBA

The crowd that is moving away from the MBA programs is aged 21 to 25, has little work experience and big dreams. Granted young professionals and recent graduates may not be thinking about ROI, but they definitely know that competition is fierce when it comes to full time MBA programs and the odds are stacked against them.

I mean how does one compete with VPs of important divisions at Fortune 500 companies with just a college degree? And how does one compete with a Serial Entrepreneur with 8 different successes with just one year of "so so" work experience? Yes, apples are compared to apples, and ultimately Admissions committees do compare Consultants with Consultants, but who do you think wins - the consultant with 5 years of stellar work ex or the young associate consultant who just started out at a small company?

On top of that, being 2 years out of the work force really doesn't sit well with students who already realize how hard it is to pay the bills with a humanities degree.

Luckily, European and Asian schools gave such students a solution to their problems. The Masters in Management program.

Its generally a one year program that really prepares you for the business world. You spend less money, time and effort than you would in a 2 year MBA program and you start working at a respectable annual salary of $90k at a major corporation. Sounds like a lucrative proposition if you ask me.

Plus, you compete with people just like you. The number of applicants is less. And getting financial aid is just as easy, if not more.

Here are the FT rankings for MiM programs for 2015: Link

If you sort the numbers, you realize that ROI is high for all programs. Let us set aside Indian and German programs since the cost of living is relatively low in these countries. To make it fair, we will use salary data from Swiss Business school, University of St. Gallen to calculate ROI:

ROI for USG= 89000/55000 = 1.6  (in the very first year!)

ROI for HBS=120000/200000 = 0.6 (again first year)

Let us also not forget that other than Switzerland most of the other countries on the list have much lower living costs. Many schools charge nominal fees. And almost all of the European schools allow you to work for upto 20 hours per week slashing the costs even more.

If we decided to look at a German school such as WHU Germany the ROI comes out to be ~2.5 and that is just one year.

Now you may say, but wait a minute, maybe students don't get placements. And you would be wrong. Placements are 100% for many schools! While about 20 schools on the list have promising placement stats of 95% or more, most of the schools have figures in the 90-100% range.

Let us also not forget that it takes up to 10 years to pay off a US full time MBA loan. Here are some more though provoking payback figures published on Top MBA: Link

So, if you are young, inexperienced, do not wish to be burdened by heavy loans or simply cannot afford a 2 year MBA, perhaps you should look at MiM programs. Besides, a euro-trip never hurt anyone!

Probability questions are one of the most hated kind of questions on the GMAT. After all, the "probability" of getting the answer right (if you are a Poet) is pretty low. Although, under timed conditions, many Quants struggle to get it right too.

First of all, you don't need to worry too much about any one topic on the GMAT. It's just not worth the hassle to fret over something that might not even show up on test day! Still, if you want to get Probability questions right, I am going to give you some very basic tips that will at least help you narrow down the answer choices and eliminate the wrong ones.

So what is probability? Its the mathematical representation of "chance".

Basically, if I gave you a coin and told you to toss it just once, you will either get heads or tails. So, if I ask, what are the chances of getting heads, you might say 50%. How did we calculate that? Simple.

Number of total possible outcomes: 2 (Heads or Tails)

Number of favorable outcomes: 1 (Heads)

Simple divide number of favorable outcomes by number of total outcomes, or

Number of favorable outcomes           = Probability
Number of Total possible outcomes

1   = 0.5     Multiply this by 100 to get probability in percentage, i.e. 0.5 x 100 = 50%
2

Now, what if you don't have the time or don't really need to calculate probability?
How do you guesstimate?

Golden Rule: Always calculate the total number of outcomes first! That's it!

If you have the denominator, you will be able to eliminate a couple of choices in most questions.

After that you may or may not be able to calculate the number of favorable outcomes, but you would be able to guess better.

Yesterday, I had an extremely crucial Skype call to attend. But, for some reason technology decided to give me the slip and I wasn't even able to connect. It WAS a major setback considering that I worked for a long time just for that ONE call. Luckily, things turned out well, but even before they had turned out well, the way I reacted was amazing. For some reason, the incident had fired me up instead of making me feel disappointed.

My thought process was: Even if I get 30 seconds, I am sure I will be able to get my message across.

And I noticed that reaction and thought to myself, "What is going on? Is this how I always react to setbacks? With more energy and determination?" And the answer from all levels of my conscience was a resounding YES!!!

That's the reaction that GMAT test takers must have when they face setbacks on the way to their dream score!

Then, a friend of mine shared a link to Tim Grover's book and said I might find it useful:
Relentless: From Good to Great to Unstoppable

Of course, I have followed Tim for a long time, but never read the book. For the uninitiated, Tim Grover is the man who trained Michael Jordan, Kobe Bryant, and Dwayne Wade (along with countless others), and helped these amazing super-performers become "Unstoppable". There a lot of "Self-help" Gurus out their, but how many can claim to have churned out superstar after superstar?

When I was done with the book, it struck me - everything that Tim says in his book applies to GMAT as well. I mean ultimately, most first time GMAT test takers do not score their dream scores. Usually, there is a major gap between what they score and what they would like to score.

Some people close the gap quickly, and others don't.

Here's how the "Top Performers" score that elusive score after failing the first time (and how Tim's advice applies to performance on the GMAT):

1. By thriving under pressure: That's the reason 2 people who score same in practice, end up scoring different scores on Test Day! Nervousness kills performance on the GMAT!

2. By not recognizing failure: It is highly common to have to retake the test. But, most people give up after their first attempt! High performers "expect" that a retake may be necessary and simply consider any setbacks as bumps in the road.

3. By controlling the uncontrollable: Emotions, Timing, and Intellectual Stamina - these are the 3 things that need to be controlled. You can't be emotional or egoistic about some question that you couldn't answer. You must have a proper timing strategy so you don't run out of time near the end. And you must have trained yourself to sit through 4 hours of GMAT without running out of gas. Those who make a come back on the GMAT, control these apparently uncontrollable things.

By the way, on the GMAT, the test makers are your "Competition". They will try to trick you every step of the way, they will try to get in your head, and they will place a number of obstacles in your way. But, ultimately, you will triumph.

So heed Tim's advice and become Unstoppable!

Conventional wisdom tells you: If you just keep your head down, focus on learning, practice a ton of questions, you’ll achieve that score. Everyone thinks that’s how preparation works. Traditional education has ruined our ability to learn effectively – it made us take a test, get a decent score, and then move on to the next year. 

Traditional education doesn’t focus on “Analysis”. And we tend to bring that “bad understanding” of how learning and test preparation works into our GMAT preparation.

There is no doubt in my mind that hard work is one of the pillars of success. But, it’s just one of the pillars. It is not a guarantee! 

On the GMAT, you need to constantly improve. If you haven’t score 700+ on a practice test after months of hard work, ask yourself: Why aren’t you improving? 

Here's is that answer: The lack of Analysis.

Not everyone is created equal- you will either be a poet or a quant, which means you’ll be good at only 50% of the test before starting preparations. 

You’ll have to work on the other 50%.

And it’s not by brute force or hard work that you’ll get results. It’s by analyzing your tests and practicing the right way. 

I have already written about how you can do that: here

Check it out. It is my most popular post and that's for a reason!

Paradox questions confuse test takers. The question is how do I correctly answer a CR question that is paradoxical?

Usually, paradox questions say something like: "Resolve the paradox". And that is a clue! The test makers want you to resolve the paradox.

How do you resolve a paradox? Let us understand with an example:

The Mayor promised that the local economy would do amazingly well, once the new stadium was completed. He provided the logic that since tens of thousands of people would come to watch sports events every month, these people would have to stay in nearby hotels, eat at local restaurants and shop for goods from the local shops. However, sales figures show that there was no impact on the revenue of the local retailers, hoteliers . In fact, in many cases, the sales actually went down.

How do we explain this paradox?

Obviously, there has to be a plausible explanation. There could be many, but on the GMAT only one of the options given would be correct.

In order to resolve the paradox, use the Bridge technique. The premise states x, which should give result y, but in reality gives result z. So there has to be some fact that would be able to bridge the gap between two contradictory things.

Bridge technique says that you need to choose an answer choice that Proves there was no paradox in the first place!

Let us say there were 3 choices:

Choice A: The stadium itself failed to attract crowds. -> doesn't explain why sales went down
Choice B: The mayor was lying -> irrelevant to the argument
Choice C: Sports fans bought snacks and other food items inside the stadium and never had to stay overnight. Also, local people avoided shopping downtown when such events took place, because the traffic and rush was just mind boggling.

That last choice explains everything. Fans never had to stay overnight. They did not eat at local restaurants, because they visited only for games and stadiums provided enough "food" for them. Plus, since the locals avoided the local shops during events, obviously local businesses not only did not profit from the stadium, their revenue actually went down.

That choice shows that there was no paradox to start with!

So, use the bridge technique and simply pick the choice that proves there is no paradox! Other choices will either be IRRELEVANT or won't completely explain away the paradox.

Statistics are extremely important in life. But, on the GMAT, you don't need to have the skills of an economist to crack problems. Generally, the test makers rarely provide problem solving questions related to stats, but they almost always provide data sufficiency questions related to stats.

So, knowledge of some rules is all you need to tackle most DS problems related to statistics.

The most common "rule" that you should become familiar with: what happens to a stat when you add a new parameter or subtract a new parameter? Does the mean change when you suddenly multiple the same number across individual parameters? What is the one thing that rarely changes?

I'll give you the answers to all these questions in just a second. But, first let us understand why we need to know this stuff. Basically, statistics problems are trickiest when they are combined with the Data Sufficiency format. You can't or shouldn't solve anything related to a DS problem, unless you want to waste a lot of time.

So, the alternative is to know certain "properties" related to statistics, in case the test makers decide to play statistical mind games with you.

Rule 1: Any time you add,subtract, multiple or divide anything with the individual components of a series, the Mean and Median change.

For example: Mean of 2,3,4 = 3  , but if we add 1, mean of (2+1,3+1,4+1) = 4

Notice: Mean increases by 1 as well!

Rule 2: Range and Standard deviation DO NOT change on addition or subtraction.

For example, Range in the above example was = 2. Even after addition of 1, the range still remained 2!

Rule 3: Range and Standard deviation DO CHANGE on multiplication or division.

For example, if we have original series as 2,3,4 and new series as 2x2,3x2,4x2 or 4,6,8 ...
Then, the range changes from 2 to 4!

Notice: Range increases by a factor of 2 as well.

Those are the 3 rules that you should know. The example given by me should be enough for you to remember these rules.