How to prepare for Civil Services Aptitude Test (CSAT)?

CSAT paper is the gateway to get admitted to the Main Phase of Examination.Though it is qualifying in nature with only 33% marks required to clear this paper, many aspirants fail to clear this paper inspite of crossing the cut off in General Studies paper.

Infact, the difficulty level of CSAT paper in 2019 Civil Services Prelims exam was so high that even aspirants from Engineering and Science background have failed to cross the 33% threshold.

It would be prudential to analyze the paper first inorder to understand the reasons for difficulty in clearing CSAT.

Analysis of 2019 CSAT paper:-

Three broad categories of Questions can be identified in the 2019 CSAT paper

1. Reading Comprehension Questions – 29 Qns

2. Logical non-numerical questions – 10 Qns

3. Numerical Questions – 41 Qns

Category 1 – Reading Comprehension Questions

These are the questions that are asked to assess the ability of the candidate to grasp the message of the passage and to arrive at a conclusion.

Two follow up Questions are asked that tests the candidate’s understanding of the passage.

How much time can be spent to answer each passage?

Total duration of the exam is for 120 minutes.

Total no.of Passage related Reading Comprehension questions = 29

which leaves us with 4 minutes for answering each Passage as 2 questions are asked after each passage.

Hence 2 minutes can be spent for reading and comprehending the passage and 2 minute can be spent on eliminating the wrong inferences and choosing the correct option for the 2 follow up questions.

What to look for while reading a passage?

Each passage should be read twice. In the first reading, the central idea and the message of the passage should be understood so as to differentiate the Essential from the Non Essential information in the passage.

For Example, consider this passage in the 2019 CSAT question paper

Step 1:-

Read the passage so as to understand the central idea in the passage.

In the above passage,the central idea is about the changes to the environment due to human related causes. This central idea of the passage is communicated in the later part of the passage and not the initial few sentences.This central idea would be the essential aspect to be considered while reading the passage the first time.

Other aspects of the passage such as owls preying upon small mammals etc is the non essential aspect of the passage

Step 2:-

The second step is to go and have a look at the questions that are asked following the passage.

Lets have a look at the Questions that are asked following the passage.

Three statements are asked in the Question.

Why statement 1 is wrong?

The first statement is about Global Warming as a frequently occurring phenomenon . Reading the passage again we understand that nowhere in the passage is anything spoken about the frequency of the occurence of Global Warming.

Hence statement 1 is wrong.

Why statement 2 is wrong?

The second statement checks if there is any relationship between “Global Warming” and its impeding (means future) effect on small mammals.

The 4th line in the passage mentions that in the last 13000 years though the Earth had undergone heating there was no impact on small mammals.

Just because in the last 13000 years increase in temperature had no effect does not necessarily have to mean in the future as well global warming will not affect small mammals

That would be a wrong assumption to make from the past experience and projecting the same to the future since the passage also mentions that human related activities have caused a reduction of biomass and energy flow.

Hence statement 2 is wrong.

Why statement 3 is correct?

Look at the 3rd statement. It states that “human beings are responsible for the loss of Earth’s natural resilience”. the last sentence in the passage associates changes in energy flow and reduction in the earth’s natural ability to adapt. The 2nd last sentence of the passage says that Human related activities have affected the energy flow.

Hence human activities can be related to the loss of earth’s ability to adapt itself.

Hence this statement 3 is correct.

So hence the right answer for this question would be Option B

This is how each passage question should be approached within a time span of 3 minutes.

Reading comprehension questions become easy to score once the skill of “Understanding the core idea of the passage” and the method of “getting back to the passage and eliminating improper conclusions” can be mastered.

Category 2 – Logical non-numerical Questions (Highly Scoring Questions)

Logic is the only tool that is necessary to solve such type of Questions in CSAT.

This should be done with a cool mind. If we get nervous since the clock is ticking then our mind cannot perform these tasks of assumptions and then applying it to the statements and then arriving at conclusions. A simple question that could have been solved in a matter of 2 minutes ends up not being answered and this sets in a panic cycle that blocks further mental actions.

Timing each questions and spending not more than 2 mins per Reading Coprehension Question is the best way to ensure we are left with adequate time left to focus on logical questions.

But this does not mean that we should be looking at the watch after each and every question. By repeatedly practising CSAT tests atleast 10 full length tests we can set our mental clock in action and that will ensure us that we comfortably clear CSAT.

This repeated test exposure is what differentiates people who become comfortable with CSAT paper.

Let us consider the following Question.

This Question can be solved with factorial principle. But for those who are not comfortable with these principles, there is nothing to worry about.The only skill that is required here is the ability to Visualize and Imagine a cube.

The Question says that each side can be painted either Black or White.

There are six sides to a cube. Lets say A and B are opposite sides of a cube.C and D are the opposite sides and E and F are the opposite sides.

Hence there are 3 pairs of opposite sides that we find in the cube.

Lets take one pair A and B and think about in how many different ways the sides can be painted.

A is Black & B is also Black


A is white & B is also White


A is Black & B is white


A is white & B is Black

Hence there are 4 different ways of painting two opposite sides.

Similarly if C and D are opposite sides they can also be painted in 4 ways.

Similarly E and F are opposite sides and they can also be painted in 4 different ways.

So the total different ways of painting the cube in either black or white is 4+4+4=12 different ways.

Easy isn’t it?

Without knowing factorials, this question could be solved just by visualizing the Question. After visualizing, only one pair of opposite sides has to be considered about the different ways of painting them and we can arrive at the final answer. Hardly takes 2 minutes to solve if you can draw the diagram of the cube and think about it.

UPSC CSAT numerical questions are not about memorizing any formula, but rather it is all about logically approaching the question.

10th standard mathematical skills would suffice to solve these questions only if you have properly understood the problem in the hand.

Category 3 – Numerical Questions.

Similarly let us look at the other numerical question asked in this question paper in 2019 CSAT.

Though the question is about length and size, it is completely logical in nature.

The only mathematical knowledge that is required to solve this question is an understanding about what odd numbers are, what even numbers are, what happens when odd numbers are added, what happens when odd and even numbers are added and an idea about ratio. Understanding the properties of numbers is what can help solve this question rather than memorizing any formula or method to solve this.

Sunita cuts a paper into three pieces. The numerical lengths of each pieces are not given. But certain relationship between the lengths of the 3 pieces is given.

Lets name the three different lengths as x,y and z.

The Question says that the length of the third piece is equal to the sum of the lengths of the other two pieces.

Lets say from the above statement that z=x+y.————-(1)

Since one piece of paper is divided into three pieces, lets apply the ratio principle to this question.

If total length is 100, the only possibility where z is equal to x+y can be satisfied is if z = 50 ie half the original length

The question also says that the length of the second piece is first + 1/3rd length of the third piece.

y =x+z/3———-(2)

But we also know that z=x+y from (1)

Substitute it in (2)

y=x + (x+y)/3

Which can be written as

3y=3x +x +y

Bringing all x and y to one side


Hence y=2x.———(3)

We now have found that the second piece is twice the length of the first piece.

Lets draw a diagram now to represent the three pieces.Since z is half the length and length of y is twice that of x(from equation 3) we can depict the lengths in this ratio.

So the total length of the paper is 6x.

Now lets go back to the question. The Question says that the length of the first piece is the average of 3 single digit odd prime numbers.

How many single odd prime numbers do we have? 1,3,5 and 7.

Which 3 among the numbers have to be chosen?Which one should be left out?

We can waste time trying different combinations and arriving at an answer or we can apply the property of numbers here.

Any 3 odd numbers added together will always give an odd number as the result.

So we can say that x= (odd number)/2

Total length =6x( from the diagram)

Hence total length=6 * (odd number/2)

  = 3 * odd number.

So the final result has to be an odd number and a multiple of 3, which leaves us with only one option and the answer is hence B

The Question requires an understanding of the property of Numbers and the understanding of the ratio principle.

There are no difficult calculations but only application of these concepts that can help us arrive at the correct answer.

Hence from this question, it is clear that memorizing formula of probability, permutation and algebra will not be helpful in CSAT.

It is only the understanding of certain properties and concepts and knowing how to apply them that can help tackle almost 40% of the CSAT paper since this 40% are numerical questions.

The better strategy would be to solve as many tests as possible and to check for explanation so as to identify the application of properties of numbers and application of certain math related principles. It is only by following this strategy you can cross the required margin comfortably and be assured of clearing prelims.

Being assured of clearing prelims will help you start well with your mains preparation than depending upon luck to clear the CSAT paper.