Science of high performance in the GMAT -1 : Is GMAT Official guide sufficient?

Official guide- published by the GMAC has a list of 800+ questions (11th edition). There are around 230 problem solving (math) questions.. However I feel that this list represents the easier problems in the GMAT.

To break into the 720+ it is imperative that you have to solve tougher higher difficulty problems. (This is true for the verbal section also)

What is a higher order problem?
A higher order problem is problem which has
• A situation which can otherwise be solved by identifying the concept/formula and applying the same directly
• A complexity present in the problem which acts as a stumbling block, thereby preventing you from getting an answer directly.

When approaching a higher problem first

1. Identify the concept involved
2. Identify the complexity in the problem
3. Remove the complexity and if possible arrive at a result
4. Modify the complexity in such a manner the complexity gets integrated into the problem and this results in  a   newer problem
5. Solve the new problem by directly applying the concept.

Let me highlight a higher order problem. Watch how I analyzed the problem and how I solved.

A car moving at 45 kmph and is chasing a two wheeler that is moving at 30 kmph. The distance between the car and the two wheeler at 10:00 am is 48 kms. The car stops at 11:30 am for 15 mins to fill fuel and moves at 45 kmph. When will the car meet the two-wheeler?

1.12.42 pm      2.1:42 pm           3.1:57 pm          4. 1:47 pm  5. 1:30pm

Try this problem independently first, then read further.
Let me take you through the problem in the science of thinking* approach toward higher order problem solving.

The concept – Time, speed and distance, Relative velocity involving two bodies moving towards each other.
The complexity – The stoppage time of the car. At 11:30 am the car stops for 15 mins.

Eliminate the complexity first
If the car didn’t stop at 11:30 then the time taken by both the bodies to meet is determined using the relationship
Time taken to meet = Initial distance between the bodies/ relative velocity
= 48/(45 -30) { Relative velocity when two bodies move in the same direction = difference of their speeds, hence 45-30 =15)
= 48/15= 3.2hrs

Modification of the complexity
As you would have observed if the complexity is eliminated the problem can be solved directly. As per the problem. The car travels till 11:30 and then stops for 15mins. So you might calculate the distance travelled by each body from 10:00 till 11:30 and then calculate the distance travelled by the two wheeler for that extra 15mins and then proceed. This complicates the problem.
Instead you can restructure the problem in such a way that the complexity gets integrated into the problem and doesn’t get noticed.

Here you can shift the 15min time interval from 11:30 to 10:00 such that the car starts only at 10:15 instead of 10:00. Hence the initial distance increases from 48 to 48 + (distance travelled by two wheeler for 15mins) = 48 + 7.5 =55.5kms

Hence now there is no stoppage time at 11:30.
Time taken to meet = Initial distance between the bodies/ relative velocity
= 55.5/(45 -30) = 55.5/15= 3.7hrs = 3hrs 42minutes
Meeting time =10:15 + 3 : 42 = 13: 57
You would get higher order problems only if the adaptive algorithm decides that you deserve questions of this difficulty.
So for those of you who aim to crack the 720+ barrier. Practice on higher order problems.


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Pattern recognition as a skill to solve GMAT math problems

Many math problems are based on patterns. These problems may involve a set of numbers or a set of alphabets or maybe even a set of figures.

The skill is in

• Identifying patterns
• Taking a sample and deriving meaning full relationships between the various elements in the pattern
• Expostulating the pattern to encompass the entire series
• Use this new knowledge to arrive at an answer

Lets take a problem

The sum of the even numbers between 1 and n is 79*80, where n is an odd number, then what is the value of n?

This sum involves a set of even numbers from 1 to n.(n is an odd number)
Lets derive the pattern
First let n =5
Then the even numbers involved are 2,4
Hence, Sum = 2+4 = 6
6 can be written as 2 *3( Same pattern as 79*80)

Now let n =7
The even numbers are 2,4,6
Sum = 2+4+6 = 12 i.e 3*4

So you get a pattern 2*3, 3*4…………………….79*80, when n = 5,7……n
Do you observe that 2+3 =5 and 4+3 =7, 4+5 =9

This leads to the answer.

In a nutshell: when you encounter problems which ask you to compute the value for n terms
Take a small sample and analyze.(Relate the analysis to the answer)
Take another sample and analyze
Write the result together and derive a relationship among the numbers
This leads to the answer.




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How to cross the magical 700 score barrier in the GMAT -1

So you are at your fag end of your preparation. You have just completed a GMAT CAT, you got a score of 640. You also notice that your score has been hovering around 600 to 650. Well you are not alone.

A recent survey states that the average GMAT score is 560, down 10 points when compared to last years average. How is that few people cross 700 whereas the rest of the test aspirants(approximately 2,00,000 out of 2,65,000 GMAT takers) languish in mere 600’s?
Here is my 2 cent

The GMAT score is an indicative of the current aptitude level of an individual. Your aptitude quotient doesn’t improve over night. It takes at-least 3 months of preparation to improve your score. So what is POA right now.

1.Repetition
It is better to work on a question 10 times than working on 10 different questions. Aptitude exams don’t test your knowledge of formula. It tests you on your application of concepts.
Study each problem 10 times, observe the parts a problem
• Variables: elements in the problem which maybe independent, dependent or hidden vis-à-vis other variables.
• Conditions: relationships that relate variables
• Constraints: Conditions that limit the scope of the problem
These parts of the problem indicate the steps and the time taken to solve the problem. This factor results in effective time management.

2. Reason with math
To improve your math preparation, reason with mathematical problems.
For example
What is the product of 5^25 x 2^32?
To solve this sum reason with the problem:
Observe a sample and derive a pattern:
5^1 and 2^1 gives 10
5^2 and 2^2 gives 100 or 10^2
5^3 and 2^3 gives 100 or 10^3
The pattern is one 5 and one 2 gives 10, two 5’s and two 10’s gives 100…. The number of 5’s and the number of 2’s gives the number of 0’s.

Conclusion one 5 and one 2 gives one 10 or a number with one 0.
Hence 5^25 x 2^32 = 5^25 x 2^25 x 2^7
Which is 128 …….(25 times)

3. Do not revise just the formula, learn how to derive it.
Most mathematical problems in the GMAT are related to the method of deriving certain standard formula than the formula itself. For example
While deriving the area of the equilateral triangle = sqrt(3) side^2/4
You will notice that the altitude bisects the triangle into two halves of equal area
The altitude splits the base into two halves of equal length.

4. Compare critical reasoning questions and derive generalization.
Study the CR questions in groups. For example study all “the weaken the argument” questions together. You will observe standard steps every time.
For example you will observe you have
• to first find the conclusion
• then identify the logic( whether its an analogy, a statistical data, a cause effect relationship or an example)
• then choose the option that negates the logic

Simple aint’ it.

5. If you are not strong with sentence correction and reading comprehension till now and if you have only two weeks to go, then there is nothing that can be done. It requires at-least 3 weeks of structured learning.

Use any course ware you have or use the course ware which I have recommended. Its on your right pane. Or if you don’t have the right material mail me ill help….:-)



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Number of GMAT test takers

GMAT was taken 265613 times in the testing year 2009*. “Total GMAT volume is up, but by breaking down the figures by country, by world region, by gender, by intended degree, and by age, we see a very complex picture emerge,” says a senior official from GMAC.

Some highlights from the GMAC report

• The number of GMAT test takers have been rising for the past five years
• The number of tests takers under 24 continues to rise rapidly
• The percentage growth of number of tests takers has increased the greatest in central/south asia followed by Australia/Pasific islands, Europe and finally Canada.
  
• The overall mean GMAT score is down one point, to 539

* source GMAC

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GMAT sentence correction

The GMAT verbal section is the toughest section in the test. For this the section that appears after two long sections of writing and math. It induces undue strain on the test taker. Besides this section is concept intensive unlike any other aptitude test.

Besides, each question type is long sentence or paragraph based requiring extensive reading of verbal information.

The sentence correction questions (14/15) of them tests correctness and effectiveness of expression. You have to choose the option that conforms to standard written English; you have to pay attention to grammar, syntactical constructions, diction, clarity and semantic conformity.
Listed below are those concepts that you should learn for excellence in the sentence correction question.

COMMON ERRORS TESTED IN GMAT SENTENCE CORRECTION

1. Subject Verb disagreement
2. Parallel structure
3. Idiomatic constructions
4. Misplaced Modifier
5. Tense consistency
6. Countable, non-countable nouns
7. Pronoun-noun agreement
These are just 7 of the 25 errors tested in GMAT.

Read more about the errors at

http://www.semanticslearning.com/gmat-usage.asp

Examples
Misplaced Modifier: example

“Annoyed by the corporation’s apathetic attitude, it was decided by the residents to install an incinerator for garbage disposal.”

Here “Annoyed by the corporation’s apathetic attitude”, should modify the residents, hence the correct construction is
“Annoyed by the corporation’s apathetic attitude, the residents decided to install an incinerator for garbage disposal.”

Ambiguous use of which/it: example

“The intake of analgesics causes irritation in the stomach which can be avoided if it is taken in capsule form”


Here which and it are unclear are ambiguous. Which can wrongly refer to stomach, analgesics or irritation.
The unambiguous construction is
“The irritation caused in the stomach by the intake of analgesics can be avoided if the analgesic is taken in capsule form.”



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Math Problem solved using ScoT

I got a query from a in this problem. I solved using Science of Thinking(ScoT) approach.Observe the problem solving process.

The sum of the even numbers between 1 and n is 79*80, where n is an odd number, then n ?

These type of sums can be solved using my thinking skills – “pattern recognition” and “hypothesis testing”


Take sum of even numbers when n =5( N has to be an odd number)
Sum = 2+4 = 6 i.e 2 *3( Same pattern as 79*80 i.e n*(n-1))
Now take sum of even numbers when n = 7
Sum = 2+4+6 = 12 i.e 3*4

So you get a pattern 2*3, 3*4…………………….79*80
When n = 5,7……n
Do you observe that 2+3 =5 and 4+3 =7.

So our hypothesis is that n should be sum of the product of the numbers(in the form n*(n-1) which yields the sum of the even numbers.
Now lets check our hypothesis
When n =9
Sum = 2+4+6+8 = 20 = 4*5
4+5 is equal to n
Hence n can be concluded as 79+80=159

For more details visit http://www.semanticslearning.com/gmat-l3-method.asp
My math Ebook has all the thinking skills tested in GMAT.You can access the demo at
http://www.semanticslearning.com/gmat-home.asp Title GMAT higher order problem solving.

Cheers





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Great schools for MBA in Europe, Australia, Asia

Here is a list of Business schools in Europe, Australia and Asia. I have also mentioned the country also.

Feel free to add schools apart from this list

FRANCE:  INSEAD, HEC School of management

SWITZERLAND: IMD

SPAIN: Esade, IESE

United Kingdom

• London Business School
• Manchester Business School
• Said Business School
• Judge Institute of Management
• Cranfield School of Management
• Edinburgh University of Management
• University of Bath: School of management

NEW ZEALAND

• University of otago, School of Business
• University of Auckland

 AUSTRALIA

• Australian Graduate School of management
• Melbourne Business School
• Monash university
• Macquaire Graduate School of management
• Queensland University of Tech:BGSB
• Curtin University of Tech: Graduate
• University of Technology Sydney.graduate School of business

SINGAPORE

• National University of Singapore
• Nanyang Technological University

CHINA

• The business university of Hong Kong
• Cheung Kong graduate School of business
• China Europe International Business School

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GMAT reading comprehension

How to answer central ideas and organization/structure of the passage questions?
These passages are organized on certain templates. We need to know these.

Why
Because there are questions that seek you to identify the structure or organization of the passage
What are those structures?

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Analyzing GMAT math problems using the Science of Thinking(ScoT) approach

The first step in the problem solving process is problem analysis. Problem analysis comprises

• Problem Definition
• Solution length
• Problem length
• Constraints and conditions

Let me explain the process of classification of problem based on their definition now.

Problems can be classified as a poorly defined or a well defined problem.

A well defined problem everything relevant and required is clearly specified, without any ambiguity or uncertainty, such that a solution, even if it involves complex calculations can be arrived at with accuracy. You can predict the path to take or steps required to solve the problem.

A poorly defined problem much of the data & relationships are hidden or not clear.

Lets take a poorly defined problem.

A says to B: I will be three times as old as you were when I was five years older than you are. I am 5/4th as old as you will be and then you will realize that you will be double the age you were. If the sum of the future ages of A and B is 50, what are their present ages?

The data present in the above question is cryptic. The interpretation of this problem lies in your ability to attach meaning to the verb tense.

To analyze the above problem you have to represent the problem diagrammatically to understand the relationship between the variables.

Try creating a table with the past ages, present ages and future ages as the columns. Given below is a simplified version of the table.

More ScoT approaches follow this link..
http://www.semanticslearning.com/gmat-l3-method.asp



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5 crucial points to keep in mind while attempting a Data sufficiency problem

of the equation don’t match. Hence x only has to be 0.

4. Do not make any assumptions of the figure drawn. If a four sided figure is drawn with straight line, do not assume it’s a square or if a point is marked in the middle of a circular region, don’t assume it’s the centre of the circle.

5. Although Data sufficiency tests your decision making skills (choosing which statement is sufficient) it is advisable to spend some time arriving at an answer and checking whether the answer derived is always true or always false.



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5 crucial points to keep in mind while attempting a Data sufficiency problem

of the equation don’t match. Hence x only has to be 0.

4. Do not make any assumptions of the figure drawn. If a four sided figure is drawn with straight line, do not assume it’s a square or if a point is marked in the middle of a circular region, don’t assume it’s the centre of the circle.

5. Although Data sufficiency tests your decision making skills (choosing which statement is sufficient) it is advisable to spend some time arriving at an answer and checking whether the answer derived is always true or always false.



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5 crucial points to keep in mind while attempting a Data sufficiency problem

of the equation don’t match. Hence x only has to be 0.

4. Do not make any assumptions of the figure drawn. If a four sided figure is drawn with straight line, do not assume it’s a square or if a point is marked in the middle of a circular region, don’t assume it’s the centre of the circle.

5. Although Data sufficiency tests your decision making skills (choosing which statement is sufficient) it is advisable to spend some time arriving at an answer and checking whether the answer derived is always true or always false.



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For our friends in India

Wish you a happy diwali..... May god make your dreams come true.....

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5 crucial points to be kept in mind while solving a probability based problem in GMAT

1.    Calculate the numerator {Number of favourable terms} and the denominator {Total number of terms}     separately using the concepts of arrangement, permutation and combination.

2.    Be part of the problem : Imagine you are arranging / selecting the items. The action of taking     the object and placing it in the relevant position is the key.

If you have to arrange 10 rings in 4 fingers, you have to imagine yourself picking a ring and placing it on a finger instead of computing the number of rings each finger has.

3.    When two or more items are picked it is easier to compute the probability of picking one     element at a time than computing the probability of picking many items at a time.

4.    When A and B are selected relate the respective probabilities with multiplication. When either     A or B is selected relate the respective probabilities with addition.

5.    When there are multiple outcomes possible the probability of at-least one of them happening is     computed by calculating the reverse probability
 = 1 – probability of event not happening.


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5 crucial points to keep in mind while solving a permutation combination problem

1.ARRANGMENT N terms can be arranged in N! ways, if each position can be occupied by one term. N terms can be arranged in NM ways if each position can be occupied by 1 term or 2 terms or …… N terms.  M stands for the number of positions to be filled.

2.COMBINATION M terms can be selected from P terms in [ (P)combination(m) ] ways.

3.In certain situations it is required to first choose the terms and then arrange the terms. i.e.     PERMUTATION.     Permutation = combination x arrangement.

4.When N objects are distributed among P positions such that each position can get any number     of objects (zero, one, two ……N) then the number of ways of arranging the items is [ (N+P-1) combination (P-1) ]

5.When N objects are distributed among P positions such that each position can get atleast one     objet (one, two ……N) then the number of ways of arranging the items is [ (N-1) combination (P+1) ]