After the previous post a few of you had commented saying that you are eagerly awaiting the post on the DI-LR section. The earnestness is understandable since most of you who are facing the SimCATs will know that the DI-LR section is one that will make or break your CAT.
If it goes well, you will take that confidence into the QA section finish strong. If your performance on the DI-LR section goes south then you will start feeling the fatigue of 120 minutes of testing and will fade away in the last section. The latter was the case with most test-takers last year.
The CAT 2014 DI and LR sets were probably as tough as the CAT 2015 ones but since there were only 2 sections overall, and DI and LR they were part of the QA and VA sections respectively, avoiding them was easier; with the CAT 2015 paper there was no place to hide.
As a paper the CAT has always been fun to take because of the inventiveness of questions. Some of the best CAT papers — 2005-2008 — were a treat (not from everyone’s perspective) because of the high quality of the questions posed. For us test-prep professionals taking the paper-based test in December was like the culmination of a year of work; the calendar year kinda ended with the CAT. I still remember coming out of CAT 2006 and thinking about the awesome Erdos Number LR set and not resting till I solved it fully. The CAT Day would end after all of us had agreed on all the answers, which never fully happened with the VA-RC section, before putting it out for students and waiting for the Official Answer Key.
Since the test went paper-based in 2009 that sort of post-test excitement has disappeared. Not just that, the level of the paper dropped drastically as well — especially QA, DI and LR — since they had to make 40 different papers.
It was only in 2014 and 2015, when it was conducted in fewer slots, that the DI and LR sections returned to a level that could be called CAT-level.
Going by the last two CATs and the overall tilt of the IIMs towards making the test an even playing field for aspirants from all backgrounds, it is likely that the trend of keeping the QA easy and the DI-LR tough will continue. They need to level the playing the field but not the level of intelligence!
So this post will be geared towards helping you fine tune your strategy and ability with respect to the DI-LR section. We will start with strategy and then move on to the specific handling of sets.
The first step is to select the right sets across DI and LR
Of all the skills that tested on the CAT, the ones that almost essential or indispensable to a business manager or leader are the ability to interpret data and the ability to reason. So it goes without saying that you do not have a choice between liking one or the other because it is not a question of a clearing a test but the question of your very suitability for the program and career you are choosing!
So the first rule — you cannot have a favourite between the two.
Your job is to choose the right sets irrespective of whether they belong to DI or LR. On one test it can be 4 DI, 2 LR on another it can be 1 DI, 4 LR — you choose as per the paper but not as per preset rules. There is a difference between playing preset tunes on an electronic keyboard and actually playing the keyboard.
So this straight-away eliminates the problem of how to allocate your 60 minutes. You scan all the sets and choose the 4 easiest ones to start with and then pick two more if the time and the level of difficultly permit.
This is very important in the context of the current nature of DI-LR sets.
The tougher the DI-LR section gets the harder it will be for your say where DI ends and where LR behind, the lines between the two get really, really blurred. So you will be better off setting your goal to be to choose and do 5-6 sets among 8 sets in 30 minutes.
Let’s take a look at the DI-LR Sets in SimCAT 2, which had a DI-LR sectional cut-off of 21, to see how this choosing is best done.
How to choose the right DI and LR sets
Before we jump into the DI-LR sets of SimCAT 2, we should define a few terms for ourselves.
Standard Set versus Unique Set
We know what standards sets mean — these are the staple of most LR section — Linear Arrangements, Matrix Arrangements and the most standard one of them all, the good ol’ Sports Set! It got without saying that we do not need to define what Unique Sets are.
Plugin Conditions versus Deductive Conditions
Not all conditions are alike. There are broadly two types of conditions
- Plugin Conditions that can be directly represented in a table — Ajay was from Bhagalpur or the Navin is not an Architect.
- Deductive Conditions are those cannot be directly inserted into a table but will yield information when used with plugin conditions that can then be represented in a table. The deceptive conditions can be
- purely logical in nature such as no two players scored the same number of runs or
- numerical as well such as the average weight of the five tallest people was 3 kg lower than the average of the five shortest people
Open Sets versus Closed Sets
Another thing which is probably the most important thing to determine while you are reading a set is whether it is a closed or an open set.
What do I mean by an Open Set?
An Open Set is one where the set is never fully solvable or the table can never be fully completed.
There are a set of conditions based on which there can few or many possibilities, tree-diagram, and hence the questions will end up being based
- only on the information given provided, you are not expected to crack the whole set and/or
- the question itself will provide additional information — if X is present in the group then in how many different groups can be formed — which you have to use to arrive at the answer and/or
- questions involving inequalities or conditionalities
- answer options have CANNOT BE DETERMINED
Hence, to evaluate whether it is an open or a closed set you have to quickly browse through the questions as well.
If you have understood these classifications properly or in other words if you have been able to relate these classifications to the sets you have practiced then you will easily agree that the easiest ones will be Standard & Closed sets with Plugin Conditions.
As each of these three settings — Standard, Plugin, Closed starts to change the sets will get progressively harder with the toughest ones being Unique, Deductive and Open Sets.
So your first task is to read a set in under three minutes evaluate it through this lens.
Once you evaluate it you have to rate on a scale of 1 to 10 with 10 being a cakewalk set that you can solve in 5 minutes to any set that needs to be left alone being classified as 5 or below.
I know this is easier said than done but if you solve enough sets you will develop this judgment.
Let us take each of the Sets in SimCAT 2 and do this exercise. Please read the set, evaluating and classifying it as you read, before you read my take on it.
While there have been sets that involve carry-over of numbers from one year to the next, at this stage of your prep you would not have seen too many of this type.
Also from the questions it is clear that it is a closed set that will need you to deduce all the missing values to answer the questions and hence definitely something that will take time.
VERDICT: Non-standard, Plugin + Deductive, Closed; RATING: 5
A standard set based on arrangements, last year’s CAT had an LR set that was very close to this and it was the easiest of the DI sets.
The conditions are deductive but it’s simple big numbers based deductive rather than averages or ratios and also it is not a set that opens into a tree diagram.
From the questions it is clear that it is partly open but there are enough conditions given and hence worth taking a shot at.
VERDICT: Standard, Plugin + Deductive, Open; RATING: 7
While it is Venn diagrams it is not a standard set since there are no totals or any other values given apart from percentages!
There are barely any conditions given and hence it is a numerical deduction set where your comfort with numbers and fractions will get tested.
Two questions have given additional information and hence the set is fairly open.
VERDICT: Non-standard, Deductive, Open; RATING: 6
Again a very non-standard set with a lot of missing values. It is definitely deductive since they have given ratios from which one has to derive the numbers.
The questions are all direct which means that the set is a closed one and you might have to fill in all the numbers before you can answer and hence a potentially time-taking sets.
VERDICT: Non-standard, Deductive, Closed; RATING: 6
While it might look complicated it is still constructed along standard matrix arrangement lines.
None of the conditions can be directly plugged in, all of them have to be used to deduce information but there are enough conditions given.
All the questions are direct with no additional information given in the question; the first question has a CANNOT BE DETERMINED but since both that question and all others are direct one can safely surmise that they are selling you a dummy. So in essence it is a closed set albeit a time-taking one.
VERDICT: Standard, Deductive, Closed; RATING: 7
SET 6: In the image above
Again a very standard arrangement type of a situation that is not very far away from one’s comfort zone.
The conditions are a mixture of plugin and deductive.
The questions while asked in a non-standard way, they still indicate that it is a closed set more or less.
Also, it does not look like something that will not take a lot of time since it is only 5 people and 5 cities.
VERDICT: Standard, Plugin + Deductive, Closed; RATING: 7
While it is similar to a circular arrangement it is still fairly non-standard.
The conditions are all deductive since specific positions are not given but only relative positions.
The questions have additional information and hence it is definitely an open set with many possibilities. While the set itself is not difficult it might be time-taking and has scope for silly mistakes.
VERDICT: Non-standard, Deductive, Open; RATING: 6
SET 8: In the image above
A very standard set with if then conditionals that are all plugin types but the questions are essentially open.
Each question has a condition given based on which the possibilities narrow down.
While the fact that the questions look like P&C might make it scary, the fact there is no need to structure or represent the data makes it less time-taking. A set that you might be tempted to leave at face value because of the TITA factor as well but with permutation and combination it does not make a difference if it is TITA or not!
VERDICT: Non-standard, Deductive, Open; RATING: 7
You should make a list of the ratings for each set on your scrap paper so that you can have it handy.
SET 1: Non-standard, Plugin + Deductive, Closed; RATING: 5
SET 2: Standard, Plugin + Deductive, Open; RATING: 7
SET 3: Non-standard, Deductive, Open; RATING: 6
SET 4: Non-standard, Deductive, Closed; RATING: 6
SET 5: Standard, Plugin + Deductive, Closed; RATING: 7
SET 6: Standard, Plugin + Deductive, Open; RATING: 7
SET 7: Non-standard, Deductive, Open; RATING: 6
SET 8: Standard, Plugin, Open; RATING: 7
Some of you might rate sets differently based on your own capabilities, which is absolutely fine provided the set matches your estimate of it when you solve it.
Ideally you should not jump into any set without having seen all the sets. It might seem time-consuming but this time is more likely to result in marks at the end of the section rather than jumping into a set and getting stuck for 15-20 minutes.
Only if you rate a set 8 or above should you try to go for it straightaway.
One of the things that you need to remember about the CAT is that if it’s tough for you it’s tough for everyone else and the cut-off will be lower than usual. So do not be perturbed by the fact if you find most of the sets ina particular test to be tough.
How will gauge the overall toughness? By doing such an exercise for all sets.
If half of more of the sets are below 7, then is definitely not an easy section.
In this paper there are only 4 sets at 7 and none above it. If there were a few sets that were 8, then it would mean that you will have time left to take a shot at a few 6s but that is not the case.
So you know that you need to buckle down and get as close as possible to answering 4 sets correctly.
Also you will know by now that you have a match on your hands, given the highly deductive nature of all the conditions and that you have to concentrate hard to ensure a good accuracy, which will be key.
So in this SimCAT if you managed to solve sets 2, 5, 6 and 8 you will have cleared the cut-off, which was 21, very easily.
A few DON’Ts in terms of how to evaluate a set:
- do not assume a set is easy because it has a simple pie-chart or table
- do not assume a set is hard because it has a big table
- do not assume a set is hard because it has more than 1 table or chart
- do not assume every sports set is easy and hence something you should play
We will take up a few of the above sets for discussion to see how you can take your DI-LR ability the next level.
Think about how to represent the data on your paper
The first and most crucial task to decide how you are going to represent your data. For this you need to first view this exercise in the right perspective.
What do you want to achieve by representing the data?
- Most test-takers think representation is about somehow getting all the data from the screen to the paper!
With this mindset they end up doing a LEVEL ZERO representation.
What is a LEVEL ZERO representation?
Your table chart or whatever format you choose is a direct representation of the information given. It is not drawn in such a way that the output of your representation is the answer to the questions asked.
You should not try to cram everything into your representation. What happens as a result you find yourself at a loss to put in all the data, especially when there are many variables. You should try to represent it in such a way that when you complete your table it will give you the answers to the question.
So draw a table that will help you enter your inferences rather than one that will help you only enter existing data!
This is best illustrated by the first set I would attempt among the shortlisted sets, which is SET 6, since it seems to be the least time-taking.
If you have not done this set, you should take a shot at it now.
On the face of it seems like a three variables set — Trip-Home-Destination, but is it really so?
Let’s talk our way through the process:
- one man’s destination is another man’s home
- since we know every man’s destination in terms of friend’s name, all we need to know is everyone’s home town.
Since they have given you all the five trips the standard response might be to make a two by two table with names of people on both sides and then try to fill up the names of the places:
Another response might be to make separate tables or columns for home and destination but do you need separate columns for both. As discussed knowing one is knowing the other?
What is the most optimum representation?
Since you already know the trips and the unknown is the home/destination, are you not better off to having the five places as one of the axis and the trips as the other? So what is the best way to represent?
Write the trips on one side and the cities on the other.
You map the first name of the trip to the hometown using crosses and ticks based on the information that is given in the conditions and in the table as incorrect.
Since every guy can have only one home town, every row and column can have only one tick, so if there are four crosses the other one has to be tick and if there is a tick the others have to crosses.
So based on the information, you table should look like this. The only possible banana skin is the confusion between Ahmedabad and Ahmednagar!
The key to this set as is the case with most sets is finding the right representation at the beginning.
How to ensure that you structure and represent the data optimally
- Do not start writing or transferring data from the screen as you read
- The first lines in a set often contain preliminary information that introduces the set.
- If you straightaway start making a table you will be starting with the least important or lower-order information — a list of names and cities etc
- Once you reach the important information, the conditions that are given and the deductions that need to be made, you will be subordinating them to the structure of the lower-order information
- You will then try your hand at solving it and usually end up re-drawing the set
- Once you finish reading think about the best way to draw based on the conditions given (not the initial information) and the things you need to determine
This is a small but often overlooked aspect of aptitude testing. Test-takers spend very little time thinking about how to solve — they are usually reading and writing in auto-pilot mode , with very little pure thinking time between the two.
It might seem like a waste of time but a couple of minutes spent thinking, which will always seem like an eternity, will save you 10-15 minutes spent in solving sets twice!
Think of the structuring an LR set as similar to preparing the plan of a building — one does not start assembling the bricks to build a structure without a plan.
All conditions are not equal
The next set we can look at same is SET 5.
One of the keys to effective representation is to not to always view it as a matrix, especially when are many things to map as is the case with this SET.
When faced with such a set, try to visualise the representation as a set of rows in the final format that you want the data.
What do you want in this case for each guy?
MARKS, NAME, FATHER’s NAME, SURNAME.
What is fixed are the MARKS, so write it left most and do your deductions and keep entering the names, father’s names and surnames next to each mark.
While this set might seem tough there is a long list of conditions given and as we evaluated earlier it is a closed set, so it can be cracked provided you are methodical.
When solving LR sets, especially when dealing with conditions test-takers tend to gravitate towards the easy conditions, the plugin type and leave out the deductive conditions. They then waste time trying to complete the set without having deduced anything from the tricky conditions.
All conditions are not made equal, the tougher conditions are the anchor conditions that will help you crack the whole set. They are there for a reason and the reason is not for you to ignore them!
In this set what are the anchor conditions?
Conditions 3 and 4 are the anchor conditions that you need to use in conjunction with the other conditions.
When you read such conditions do not be passive, consciously try to deduce the implications.
- The student whose surname is Hirwani scored 20 marks more than the student whose father is Dattatrey, who in turn scored 20 marks more than Ajay (H > D > A)
- The student whose surname is Ganeriwala scored 20 marks more than the student whose father is Gangadhar, who in turn scored 20 marks more than Bharat ( G > G > B)
Hirwani and Ganeriwala are both higher than Ajay and Bharat respectively by 40 marks.
- If they are greater by 40 marks then they have to score either 50 or 60 since the lowest score is 10 and the highest is 60.
- Condition 5 says that Gaurav scores 40 more than someone so, he too must have a score or 50 or 60.
- So his surname must be either Hirwani or Ganeriwala, it cannot be the latter since it will start with the same letter, G, so it has to be Gaurav Hirwani at 50 or 60.
The best way to crack open the set is to take Gaurav Hirwani at 50 and see if you are able to complete the set with the remaining conditions, else he has to be at 60.
This is how the set will look once completed.
The key is to ensure that you are always circulating through all conditions looking for conditions you have left unused. Oftentimes, it happens that test-takers forget the first condition or a condition that is a second half of another one. So as a process keep going through all conditions as you are proceeding with the set.
Remember at every stage of solving it is the unused condition that will lead you to completely cracking the set.
This post is already quite long. So it best we take a break here and look at the remaining to-do sets of SimCAT 2 and my favourite CAT LR set of all time in the next post!