New Quant-DI New Strategy for Online CAT 2009

Posted by TCYonline.com on September 18, 2009

“There is no need to panic, guys;
CAT 2009 is no different from any past CAT as regards Quant & DI.”
As a serious CAT-09 aspirant, do you completely agree to it?
Although there is no need to panic, CAT 2009 is certainly different from the past CAT as regards the right ways to approach it. We have been assured many times through official notifications about CAT 2009 that IIMs are trying to keep the test as close to the old-paper-pencil-based pattern as possible. The freedom offered in a Linear-Computer-Based format supports their claim. However, the fact that it will be held on a computer screen is strong enough to make us re-visit our test taking strategies. The need to reduce or counter-balance the time-wastage-per-question, which seems to be a certain outcome of reading the data from computer screen, cannot be over emphasized. This, together with the fact that CAT Quant & DI are getting more reasoning oriented, would prove our excessive dependence on the quick-calculation-faculties a mere illusion. This mirage, if not dealt with carefully today, will anyhow disappear in November end. Nevertheless, today’s mistakes would be tomorrow’s blunders.

THE LOGIC PREVAILS
Past few years have proven to each serious MBA aspirant that a 99.99 Percentile in CAT is beyond quick calculations and Vedic Math. Though these skills are essential to set the mood, they hardly have helped a CAT taker who does not know how to logically approach a Quant or DI problem. Probably, that’s the reason why test makers are turning towards more logical problems and less calculation-thirsty sitters. Your MOCK Online CAT scores stand witness to the hard fact that as the Quant and DI problems turn more logical the time per question is bound to increase. This is because a logical problem needs a logical solution and to break the code you must spend time analyzing the given data. Hence, there is a need to curb this time-flu before it causes major damage.

A HOLISTIC APPROACH
If we analytically assess the challenges a computer can pose, we can reach the so called Holi-grail strategy for CAT-09 Quant and DI. The analysis by TCYonline experts broadly exposes 5 major challenges a CAT 09 Quant or DI problem can pose. They are:
1. Concentration
Challenge… which is the root cause of “having to RE-RE-RE-Read” a question statement / answer choices / a chart / an equation in order to un-lock the relevant information in it.
2. Optical-Illusion Challenge… which leads us to assume the “Not-otherwise-givens” thereby deviating from the logic and falling into the set trap.
3. Challenge of Relevance… which, if ignored, may push us into the data-ware-house-of-the-chart or graph.
4. Challenge of Consistency… which although a by-product of poor concentration on computer screen, can challenge our capability to stay consistent with a single unit of the data – especially the one used in the answer choices.
5. Challenge of Interpretation… which is caused by many statements which are difficult to retain in mind (because you cannot highlight any of them).

And there is only one way to meet these challenges – “Common-sense”. However, it can be easily translated into specifics as follows challlenges:
• Concentration• Optical-Illusion
• Relevance>• Consistency Interpretation
This has been explained in an example from past CATs below
Here are a few examples from the Past CATs:

Concentration
Question 1: In a tournament, there are n teams T1, T2, …,Tn, with n > 5. Each team consists of k players, k>3. The following pairs of teams have one player in common:
T1 & T2, T2 & T3, ……., Tn – 1 & Tn and Tn & T1
No other pair of teams has any player in common. How many players are participating in the tournament, considering all the n teams together?
(1) n(k – 1)
(2) k(n – 1)
(3) n(k – 2)
(4) k(n – 2)
(5) (n – 1)(k – 1) (CAT 2007)
Solution 1 :
Such question statements demand good concentration. Here, the given pairs confuse us. However, if we start formulating the problem on the scratch paper as we read, life gets easier.
For instance, Our notes go something like this:
 There are “n” teams
 “k” players in each team
 “n” pairs (the confusing part was this simple) of teams have 1 player in common.
So, the answer is nk – n = n (k– 1).
Answer (1)

Optical-Illusion
Question 2 : In the figure, AB = BC = CD = DE = EF = FG = GA. Then DAE is approximately

1) 15o
(2) 20o
(3) 30o
(4) 25o
( CAT 2000)
Solution 2: It is given that AB = BC = CD = DE = EF = FG = GA; However, in the figure, these sides do not seem to be equal. Hence, in order to accurately reach the solution, we have to proceed with the given data and NOT according to the given figure.

Work from the choices.
If we put A = 15, then C = 15 (isosceles) and then keep calculating the angles further we can reach the solution fast (for this you must have drawn the figure on to the scratch paper).
Make adjustments in your assumptions by keeping in mind that the sum of angles of the big triangle must be 180o
You will find that only 25o comes as the result.
Answer (4)

Relevance
Question 3 :

(Note: Availability is defined as production less export.)

In which year during the period 1996–99 was Chaidesh’s export of tea, as a proportion of tea produced, the highest?
(1) 1996
(2) 1997
(3) 1998
(4) 1999
(CAT 2003)
Solution 3 : A lot of data, isn’t it?
But if you really refer to the question first you will find that in order to answer it, we don’t at all require the first chart. Just concentrate on the required data to solve this question.
From second chart we can say that it is highest in 1997.
Hence, remember – the more you read without referring to the question, the more you’ll get confused (and therefore waste time).

Consistency :Directions : Eighty five children went to an amusement park where they could ride on the merry-go-round, roller coaster, and Ferris wheel. It was known that 20 of them took all three rides, and 55 of them took at least two of the three rides. Each ride cost Re 1, and the total receipt of the amusement park was Rs 145.
Question 4 : How many children did not try any of the rides?
(1) 5
(2) 10
(3) 15
(4) 20
Question 5 : How many children took exactly one ride? .
(1) 5
(2) 10
(3) 15
(4) 20
Solution 4 & 5:
Total children = 85
Children who have taken 3 rides = 20
Children who have taken 2 rides = 55 – 20 = 35
Children who have taken 1 ride = 145 – (20 × 3 + 35 × 2 ) = 15
Children who have taken 0 rides = 85 – ( 20 + 35 + 15) = 15.

Therefore, if we put all the given information in a consistent way, we can answer both the questions together.

Interpretation :
Question 6 : A chemical plant has four tanks (A, B, C and D), each containing 1000 liters of a chemical. The chemical is being pumped from one tank to another as follows:
From A to B @ 20 liters/ minute
From C to A @ 90 liters/ minute
From A to D @ 10 liters/ minute
From C to D @ 50 liters/ minute
From B to C @ 100 liters/ minute
From D to B @ 110 liters/ minute

Which tank gets emptied first and how does it take (in minutes) to get emptied after pumping starts?
(1) A, 16.66 (2) C, 20 (3) D, 20 (4) D, 25 (CAT 2005)
Solution 6 : Would you take the chance to write all the data on the paper again???
Hey! You have got to work smart here!
Just put the given information in the required format.
–A ———– B—————-C———-D
- 20 ——- + 20———–+ 90 ——- – 90
- 10———+ 10 ———- – 50——- + 50
- 100——–+ 100——– + 110—— – 110
50 liters is going away from tank D every minute. Hence it will get emptied first and in 1000/ 50 = 20 minutes.
Answer (3)

A few more things one can exercise in his MOCKs are:
• Keep in mind the same old plan of doing the paper in 3 rounds. Now as the test is on computer you must follow a very logical approach to select the questions in Round 1 and 2. For instance, In DI you must attempt the questions that can be answered by read minimum information from the graphs / charts. In Quant, ones involving minimum equations should be preferred. Also, sometimes there are 2 – 3 questions based on one set of data. They are also expected to consume less time once the problem is properly drawn on to the scratch paper. Here we are assuming that Prometric will allow you to move back and forth among the questions. However, if it did not allow (highly unlikely) you to move back, your time per question will definitely increase as you will have to skip a question only if you know you cannot do it at all given the fact that you will never come back to it.
• Also it is expected that as the test goes online the percentage of Data-Sufficiency question will increase. Moreover, it is also expected that the amount of data in the Graphs and charts will be less and with a logical approaches described above you would be able to come up winners!

All the Best!!!