1. Decision Making Problem solving & communication
    1. Bad decision choices
    2. Good decisions
    3. Just eliminate two bad decision
    4. CSAT 2013 Questions
    5. Elimination doesn’t always work though!
    6. Where to get practice?
  2. Maths: Medium priority topics
    1. M1: Arithmetic Progression (AP)
    2. M2: Coordinate Geometry
    3. M3: Polynomials & Quadratic equation
  3. Maths: Low priority topics
    1. L1: Geometry theory (TQC)
    2. L2: Trigonometry
    3. L3: Permutation Combination Probability
    4. L4: Statistics
  4. Appendix: Download links
    1. A1: Last three years official CSAT papers
    2. A2: NCERT Mathematics Topicwise Sorted free download
    3. A3: Quant books: What to prepare, what to skip?

So far in the CSAT paper-2 study plan

  1. Comprehension and Reasoning
  2. Mathematics & Data Interpretation: high priority topics
  3. Decision Making + Mathematics: Medium & low priority topics You’re here

Decision Making Problem solving & communication

First read following articles:

  1. [Decision Making] CSAT 2011: official question and answers
  2. [Decision Making] CSAT 2012: official question and answers
  3. [Decision Making] CSAT 2013: (official answer released and included in present article.)

Overall we can see following pattern:

Theme 2011 2012 2013
Office tension: project deadline, Khaddus Boss, idiot subordinates, colleagues seeking favors 2 4 1
Interaction with Goonda-log, corrupt babu 1 1 1
Roleplaying Govt. officer in situation where he could be blamed for corruption, apathetic 3 0 1
Distribution of precious commodity: sugar, vaccine, water, sarkari-house etc) 1 1 2
Communication 0 0 1
Misc. problems (dowry victim, sport chairman) 1 1 0
Total Questions 8 7 6
% weight out of 80 Questions 10% 9% 8%

Bad decision choices

From official answers, we can see UPSC hates following type of choices:

  1. Pliable guy:
    1. bribe giver
    2. bribe taker
    3. choses to look the other way while others are involved in wrongdoing,
    4. Easily gets scarred or intimidated.
  2. No discipline guy:
    1. shows Arrogance
    2. Insubordination: lack of respect towards authority, Goes on leave without telling boss etc.
    3. liar, Gives excuses instead of doing his job.
  3. Implausible, impractical choice e.g. free water or electricity to everyone irrespective of his income status.
  4. “Take no action” guy: prefers status quo, takes no action, “Committee mindset”
  5. Biased officer, apathetic officer, evasive officer.
  6. Short term oriented. A decision that will break office discipline in long term.

Good decisions

From official answers, we can see UPSC hates following type of choices:

  1. Humane e.g. giving free water / electricity but only to BPL
  2. Punctuality, meets the deadlines
  3. Upright Honest person
  4. Atleast trying to do take some “positive action” rather than continue with status quo

Just eliminate two bad decision

In Decision Making questions, there is no negative marking. And as per official answerkey-two possible correct answers. (Which of them is best? UPSC doesn’t tell)

But still, this reduces the effort. Instead of looking for right answer, just eliminate two baddest worst answer choices using the list given above. Then you’re automatically left with right answers. Pick any one based on which you think is right for the given question.

Let’s try…

(2012) You are handling a priority project and have been meeting all the deadlines and planning your leave during the project. Your immediate boss does not grant leave citing the urgency of the project. You would ____.

  1. Proceed on leave without waiting for the sanction (indiscipline)
  2. Pretend to be sick and take leave (liar)
  3. Approach higher authority to reconsider the leave application.
  4. Tell the boss that it is not justified.

So A and B automatically eliminated. We are left with correct answer C or D.
Ok 2012’s official answerkey is available. So I or anyone can ‘fit’ the logic after knowing official answers! let’s apply this technique for CSAT 2013, where official answerkey is not available. (When official answerkey comes, after final result – we’ll see how apt this approach is. update Jun-26-2014: official answerkey released and all of following answers turned out to be correct, except slight difference at just one place in family planning.)

CSAT 2013 Questions

Q. House allotment problem: Secretary wants house because his father ill. But HQ said no.

  1. Call him over to your room and personally explain why the allotment cannot be done.
  2. Allot the house to him to win his loyalty. (biased, will break office discipline)
  3. Agree with the office note to show that you are not biased and that you do not indulge in favoritism.
  4. Keep the file with you and not pass any orders. (status quo guy)

Thus we are left with two choices: A and C. (But are they really correct? we’ll see when answerkey comes.)

Q. you’re passenger, Taxi driver gives bribe to transport office

  1. Go up to the counter and ask the clerk to give back the money which he has illegally taken.
  2. Do not interfere at all as this is a matter between the taxi driver and the tax authorities. (pliable)
  3. Take note of the incident and subsequently report the matter to the concerned authorities.
  4. Treat it as a normal affair and simply forget about it. (status quo)

Again after eliminating bad decisions, we are left with A and C.

Q. You’re DM, a village came long way to submit complaint but you’re busy with work.

  1. Tell him to wait for another two hours till you come back from your next meeting. (Apathetic)
  2. Tell him that the matter is actually to be dealt by a junior officer and that he should give the application to him. (Evader)
  3. Call one of your senior subordinate officers and ask him to solve the villager’s problem. (this is not evader because asking ‘senior’ subordinate to “solve” problem.)
  4. Quickly take the application from him, ask him a few relevant questions regarding his problem and then proceed to the meeting.

We are left with C or D
Q. You’re DM. There is sugar quota order but friend asking additional supply for marriage reception

  1. Release the extra amount of sugar which your friend has requested for. (biased officer)
  2. Refuse your friend the extra amount and strictly follow the rules.
  3. Show your friend the copy of the Government instructions and then persuade him to accept the lower amount as prescribed in the rules.
  4. Advise him to directly apply to the allotting authority and inform him that you do not interfere in this matter. (Evader. because friend may try to pursued that other officer saying “I’m best friend of DM”.)

We are left with B or C
Q. You are in-charge of implementing the Family Planning programme in an area where there is a strong opposition to the present policy. You want to convince the residents of the need for keeping small families. What would be the best way of communicating this message?

  1. By logically explaining to the residents the need for family planning to improve the health and living standards.
  2. By encouraging late marriages and proper spacing of children. (ya but how do you “communicate”?)
  3. By offering incentives for adopting family planning devices. (ya but he’s asking you to “Communicate” this message?)
  4. By asking people who have been sterilized or are using contraceptives to directly talk to the residents.

We are left with A or D
Update Jun-26-2014: UPSC uploaded official answerkey, the correct answer is “A or C”. Hence this is the only place where our technique didn’t work 100 accurately.
Q. You’re setting university paper. Colleague asks you for this paper so his son can clear last attempt. he has done favors in past.

  1. In view of the help he had given you, extend your help to him. (biased guy)
  2. Regret that you cannot be of any help to him.
  3. Explain to your colleague that this would be violating the trust of the University authorities and you are not in a position to help him.
  4. Report the conduct of your colleague to the higher authorities. (too extreme, given that he had helped in past).

This one is hard for “two eliminations”. Because B, C and D all sound legit. “C” seems to be the best alternative though. Actually B=C. But C is “communicating” the message in better way than “B”.

Anyways final judge UPSC’s official answerkey.

Elimination doesn’t always work though!

Sometimes statement is open to multiple interpretations and if you drag the logic then it leads to a track away from official answer key. Consider this problem:

Q.You are a chairperson of a state sports committee. You have received a complaint and later it was found that an athlete in junior age category who has won a medal has crossed the age criteria by 5 days. You would…

  1. Ask the screening committee for a clarification
  2. Ask the athlete to return the medal
  3. Ask the athlete to get an affidavit from the court declaring his/her age.
  4. Ask the members of the committee for their views

The statement says “later it was found that….he has crossed age by five days” => so on that interpretation even “B” seems a right answer because if he cheated on age, then chairman should take back his medal. But official answer is A or D.

But such odd questions are in minority. And even in worst case you should tick an option anyways because there is no negative marking in the Decision Making questions.

Where to get practice?

Various Publication houses came up with separate books but hardly few UPSC level question. Most of them is just bolbachhan about Plato, Kautilya etc. (sometimes even copied from Wikipedia!) Hence their content doesn’t justify the price tag. (just like their comprehension books for CSAT)

Nonetheless, hit the library go through following:

  1. Pratiyogita Darpan’s SSB Group Task/Interview related articles. They don’t usually contain MCQs with 1,2,3,4 choices, but you’ll still get good problems and case studies.
  2. Civil service Times (CST): their mock test papers
  3. CSAT aptitude manuals TMH, Arihant, Pearson (whatever is available free in the library or temporarily borrow from a friend in exchange of some good book from your side.)
  4. you’ll find some demo questions here too: Mrunal.org/ethics

Anyways, moving to the next issue:

Maths: Medium priority topics

Medium priority =only while allot time for various topics in your study schedule for paper I and paper II.
These medium priority topics are rarely asked in UPSC. But they’re are not difficult, very few variety of questions, you have to memorize just 3-5 formulas. require barely ~2 hours study practice for 1 or 2 NCERT chapters.Hence you should definately try to make time in your schedule for them.

For UPSC examiner, there is no such “medium” priority, he is free to ask whatever he wishes from upto ClassX.

M1: Arithmetic Progression (AP)

(2011) A contract on construction job specifies a penalty for delay in completion of the work beyond a certain date IS as follows : Rs. 200 for the first day,  Rs. 250 for the second day, Rs. 300 for the third day etc., the penalty for each succeeding day being 50 more than that of the preceding day. How much penalty should the contractor pay if he delays the work by 10 days? Ans.4250

NCERT Class10 chapter 5

Page what to focus
116 summary mugup the formulas
105 example 10
107 Q19 and 20
111 example 16
113 Q15. Similar question asked in CSAT 2011
113-14 Q.16 to 20
115 Q.3 to 5

Beyond that your quant book for additional practice. Geometric progression (GP) starts from Class11, so far not asked in prelims so you may ignore.

M2: Coordinate Geometry

  1. [1995] In the Cartesian plane, four points P,Q,R,S have co-ordinates (1,1), (4,2), (4,4) and (1,4) respectively. The area of the quadrilateral PQRS is __? Ans 7.5
  2. [1999] At a given time, two players are standing on a play-field. The Cartesian coordinates of their locations are (20,60) and (-40,-20) units. What is the distance between the players? Ans. 100 units

As such coordinate geometry is rarely asked in UPSC. But, Coordinate geometry is not tough. You just have to do one chapter in NCERT=At max, two hour study and calculation. So, from that angle, cost : Benefit is still quite good. You might get lucky finding one MCQ in the exam, in this cut-throat competition every mark counts.

NCERT Class10 chapter 7

172 first mugup the formulas given the summary here
161 Q1, 2
167 Q6, 10 area problems
169 example 11 to 13: triangle areas
169 example 14: understand the technique to find collinear points
170 example 15: similar question asked in 1995
171 Q 1, 2 and 4
171 Question 2 to 4

M3: Polynomials & Quadratic equation

It is part Class8, 9 and 10 NCERTs. Official UPSC syllabus says basic numeracy “upto class 10”. Although UPSC hasn’t asked this in 2011, 2012 or 2013.  But such questions have appeared in pre-CSAT era, in 1995, 96, 99, 2001. Observe

(1995) what is the value of (a-m)(b-m)….(y-m)(z-m).Ans. actually this one quite easy: m-m=0 so entire multiplication will be zero. (2001) if x2+y2=34 and x4-y4=544, then what is the value of x and y

  1. 4,3
  2. 5,3
  3. 3,5
  4. 3,4
(1996) If A=x2-y2, B=20 and x+y=10 then

  1. A > B
  2. B > A
  3. A = B
  4. data insufficient
(1999) if x+2y=2x+y, then x2/y2 is equal to

  1. 0
  2. 1
  3. 2
  4. 4

There is no need to fear, very easy questions based on basic formulas. You can finish learning the entire topic at maximum within 2 hours.

Minimum prepare this:

class ch. what to focus
8 Ch.9 Algebraic Expressions Polynomials: additions, subtraction, multiplication.
8 Ch.14 Factorization making Factors of the form (x + a) (x+ b); division of polynomials

You may avoid following chapters because I’ve not such questions between 1995-2013. These chapters/concepts are typically reserved for the SSC, CDS, SCRA and CAT exam.

9 Ch.2 Polynomials
  • remainders
  • finding value of “k” in the polynomial equation
10 Ch.2 Polynomials sum of roots, product of zeros (given on pg.30)
10 Ch.4 Quadratic Equations
  • factors of quadratic equations (QE)
  • nature of roots of QE

Maths: Low priority topics

Low priority doesn’t mean UPSC will *NOT* ask them. Low priority means, within your study time table, do them at last depending on how much free time left.

First allot time for

  1. high priority topics such as history, polity, science, economy, environment (for Paper I) and those reasoning-comprehension & other high priority topics under Maths (for Paper II).
  2. then medium priority math topics given above
  3. and finally to the following low priority topics.

Reason: following topics not frequently asked. They’re not difficult but have many variety of questions and formulas=> each of them take more than 4 hours to master. Therefore, put under low priority in terms of study time allotment.

  1. Geometry theory: Triangles, Quadrilaterals, Circles (TQC)
  2. Trigonometry: only height n distance
  3. Permutation Combination Probability
  4. Statistics

L1: Geometry theory (TQC)

Geometry image based Qs

(Prelim 1998) LMNOP is a semicircle with centre at R and diameter LP. LSR and RQP are also semi-circles with centres at T and U respectively and diameters LR=RP=1/2 LP. What is the ratio of perimeter of LMNOP and LSRQP?

CSAT_DI_semicircle within semicircle

Ans. 1:1

(Prelim 2000) in the given figure, all line segments of the shaded portion are of same length and at right angles to each other. What is the area of the shaded portion?
CSAT_DI_area of shaded figure
Ans.52 cm2

(Prelim 2001) in the given figure ABCD is a cyclic quadrilateral. if AB=BECAUSE and angle BAC=70, then what is the measurement of angle ADC?
Ans. 140

Without images

[1999] If the angle of triangle are in the ratio of 4:3:2, then the triangle

  1. Is obtuse angled triangle
  2. Has one angle greater than 80 degree
  3. Is a right triangle
  4. Is acute angled triangle (this is the right answer)

[2000] Which one of the following has a greater perimeter than the rest?

  1. A square with the area of 36 sq.cm.
  2. An equilateral triangle with a side of 9 cm
  3. A rectangle with 10 cm as length and 40 sq cm as area. (this is the right answer)
  4. A circle with a radius of 4 cm

These questions mostly deal with angle, side related theorems of triangle, circle and quadrilaterals. These type of sums have been asked in earlier prelims, but in less frequency than Area-volume-perimeter. As such the list of topics, will look quite daunting but in reality its not that difficult. Lengthy yes. Difficult no.

Class_Ch Page Topic
7_6 131 summary of triangle properties
8_3 43 example 2
44 Q.3 and 4
51 Q7,8 and 9
56 Summary- properties of all quadrilaterals.
8_11 170 table for formulas
171 entire exercise 11.1
176-178 all the sums related to area of trapezium, rhombus etc.
184-185 Example 4 to 6.
186 entire exercise 11.3
190-92 All illustration, examples and formulas given in the summary.
9_6 91 pair of angles
98 6.5 transversal
101 example 4
103-04 all the angle finding questions
104 fig.6.33 fact that such mirror rays will be parallel
107-08 all the angle finding questions
108 summary
9_7 All the theorems given in this chapter. You don’t have to mug up the theorem itself but must understand how it they apply in the finding the sides and angles of any triangle. You’ll find their gist in the summary but without looking at figures, it won’t go in the head.
133 Q4
9_5 167 summary at area of triangles and parallelograms
9_8 146 Q1
151 Summary- the angle sum property and diagonals of quadrilaterals.
9_10 187 Summary-especially the properties of a cyclic quadrilateral.
10_10 213 Q.1,2 and3
214 Q12
215 summary
10_6 128 exercise 6.1 q.1
136 example 7
147 ex.11
151 q.10,11,12
153 q.10
154 summary


  1. [1997] The number of times in a day the Hour-hand and the Minute-hand of a clock are at right angles, is __. Ans 48
  2. [1998] An accurate clock shows the time as 3.00. After hour hand has 135 degree, the time would be __. Ans 7:30
  3. (2000) A clock shows 8AM in the morning. Throughout how many degrees will the hour hand rotate when the clock shows 2 o’clock in the afternoon? Ans.180
  4. [2009] How many times are an hour hand and a minute hand of a clock at right angles during their motion from 1.00 p.m. to 10.00 p.m.? Ans.18
  5. (2002) When the time in the wall-clock is 3.25 p.m., the acute angle between the hours-hand and the minute- hand is ___? Ans 47.5 degrees.

NCERT class7 deals with measuring angles, but that’s kid-stuff. For Clock problem, directly memorize the readymade formulas given in your Quant book, and practice sums from there. And in the exam, bring wrist watch and geometry compass for quick calculation (especially the 47.5 degree!)

L2: Trigonometry

I could notice only one MCQ so far

(1999) A man is standing on a 6 meter pole whose shadow length is 8 meters. IF the length of his shadow is 2.4m, what is the height of this man? Ans. 1.8 metes

There are two ways to solve above question

  1. Similarity of triangles, then take two ratios of sides. => in that case it’s a Geometry TQC problem
  2. TAN ratios (because there will be two angles with same measurement) => in that case it’s a Trigonometry problem.

Anyways, no need to consult NCERT or the Quant book for this. Because I made videos and incorporated all good sums from NCERTs within my subsequent articles. Links

  1. Youtube lecture playlist

Then articles:

  1. Introduction, Types of Questions, Shortcut for memorizing 30,45,60
  2. HnD Type #1: One Building One Angle finding height, distance or hypotenuse
  3. HnD Type #2: Broken Trees and Telegraph Poles: Finding original height
  4. HnD Type #3: One Building Two Angles
  5. HnD Type #4: Two Buildings-Two Angles
  6. HnD Type #5: Finding speed, time or distance

Ignore the other articles under my [Trigonometry] section because they’re meant for SSC and CDS, and not asked in UPSC so far.

L3: Permutation Combination Probability

(1995) A table has three drawers. It is known that one of the drawers contains two silver coins, another contains two gold coins and the third one contains a silver coin and gold. One of the drawers is opened at random and a coin is drawn. What is the probability that the other coin in the drawer is a gold coin? Ans. 0.5

(2004) Nine letters are to be dropped in three different letter boxes. In how many different ways can this be done? Ans 39

(2006) In a tournament, each of the participants was to play one match against each of the other participants. Three players fell ill after each team had played three matches and had to leave the tournament. What was the total number of participants at the beginning, if the total number of matches played was 75? Ans. 15

(2006) digits are chosen at random 1,2,3,4,5,6,7,8 and 9 without repeating any digit. What is the probability that their product is odd? Ans. 5/42

(2006) How many numbers are there in all from 6000 to 6999 (Both 6000 and 6999 included) having all digits same ? Ans 496

(2007) If all the numbers from 501 to 700 are written, what is the total number of times does the digit 6 appear? ans. 140

(2007) In how many maximum different ways can 3 identical balls be placed in the 12 squares(each ball to be placed in the exact centre of the squares and only one ball is to be placed in one square) shown in the figure given below such that they do not lie along the same straight line?

Ans. 200

(2009) In a carrom board game competition, m boys and n girls (m>n>1) of a school participate in which every student has to play exactly one game with every other student. Out of the total games played, it was found that in 221 games one player was a boy and the other player was a girl.

Consider the following statements:

  1. The total number of students that participated in the competition is 30.
  2. The number of games in which both players were girls is 78.

Which of the statements given above is/are correct?

  1. 1 only
  2. 2 only
  3. Both 1 and 2
  4. Neither 1 nor 2


(2010) when ten persons shake hands with one another, in how many ways is it possible? Ans. 45

(2010) In a tournament 14 teams play league/matches. If each team plays against every other team only once then how many matches are played? Ans.91

(2011) there are four routes to travel from city A to city B and six routes from city B to city C. How many routes are possible to travel from the city A to city C? Ans. 24

(2011) Study the following figure.. (you’ll find the figure in CSAT paper attached below)…If, A person goes from A to B always moving to the right or downwards along the lines. How many different routes can he adopt? Ans. 6

How to proceed?

  1. learn concepts from above articles, and you’ll able to solve most of the problems without needing any formulas:
    1. [Aptitude] Permutation Combination made easy without Formulas
    2. [Aptitude] PnC: arrange such that two people Always sitting together?
    3. [Aptitude] Probability Made Easy (Extension of Permutation Combination Concept!)
    4. [Aptitude] PnC: How many Ways to arrange letters of word “RECUPERATE” (Permutation without Formulas)
    5. [Aptitude] PnC: All possible numbers using 012345, All possible words using ABCDE, Permutation Arrangement Made Easy with and without Formulas
  2. Then solve NCERT Class11 Ch.7 for permutation – combination problems. (yes syllabus says  is “maths upto ClassX” but UPSC has asked PnC questions in CSAT-2011 so perhaps examiner considers this topic part of reasoning and not maths.
  3. Probability: up to class10 books cover very basic concepts, don’t have much CSAT quality questions. So go through NCERT class 11 Chapter 16.
  4. Beyond that your quant book for additional practice.

L4: Statistics

(1999) the office distribution of working hours is following

Members Work Hours
5 0-19
1 20-24
25 25-29
40 30-34
15 35-39
8 40-45

Consider following inferences drawn from the table

  1. average number of working hours is 30
  2. % of those who worked 35 or more hours, is less than 25
  3. at least five staff members worked more than 44 hours

Which of the inferences is/are valid?

  1. 1 alone
  2. 2 alone
  3. 1 and 2
  4. 1,2 and 3

Above question tests your understanding of cumulative frequency and averages of grouped data with class intervals. Such pre-CSAT questions can be asked again, because this taught in Class10 NCERT chapter 14. And upto class10 is part of the new CSAT Syllabus.

Anyways, topic not difficult all. Can be finished in less than four hours. (Hence cost: Benefit is still better than culture topic in Prelim GS.) First goto following playlist and Watch my video number 1, 3, 7, 8, 14, 17, 18 and 19.


Avoid videos related to mean deviation, quartile deviation and standard deviation they’re from class11 hence not part of syllabus. (They were part of old-mains syllabus. no longer relevant for new prelims or new mains)

Also mugup this formula: 3 Median = Mode + 2 Mean

Where to get practice?

  1. Class 10 NCERT Chapter 14
    1. Exercise 14.1, 14.2, 14.3, 14.4
    2. understand the remark given on page 279
  2. General studies (mains) paper II before 2013. Because they had these topics in syllabus.

Appendix: Download links

A1: Last three years official CSAT papers


except CSAT-2013, all contain official answerkey from UPSC

A2: NCERT Mathematics Topicwise Sorted free download


A3: Quant books: What to prepare, what to skip?

Beyond NCERT, you’ll need to practice maximum sums from your quantitative aptitude book. However, not all chapters / topics given in such books, are important for CSAT. So, consult following PDF files on what topics to focus and which topics to ignore:

  1. Fast track to Arithmetic Rajesh Verma What to prepare what to skip for CSAT
  2. Quantam CAT Sarvesh Kumar What to prepare what to skip for CSAT

Visit Mrunal.org/aptitude for more articles on aptitude, maths, reasoning.