# Prologue

In the Assistant Central Intelligence Officer (ACIO) exam, you’ve to face two papers

1. Paper I: 100 Multi-choice questions from General Awareness + aptitude (=Maths + reasoning)
2. Paper II: English Essay worth 50 marks

Total time limit: 1 hr 40 minutes

In this article, we see the approach for Maths, reasoning and English.

The approach for General awareness (History, geography, science, current affairs etc.) is given in a separate article: click me

In ACIO 2012 Question paper, the internal breakup was:

 General Awareness 79 Maths 9 Reasoning 12 Total MCQ 100

Therefore, Maths+ Reasoning=9+12=21= approx. 1/5th of paper was about Aptitude. So cost:benefit is quite good but Practice@home=essential, otherwise following things will happen:

## #1: silly mistakes in calculation

 wrong right x-5=(15/2)2*x-5=152x=15+52x=20 x=10 x-5=15/22(x-5)=152*x-(2*5)=152x-10=15 2x=25 x=12.5

## #2: formula problem

you won’t be able to recall formulas or you will plug wrong values in the formula=> either way answer will not come. (Example: area of equilateral triangle asked in ACIO-2012)

## #3: time problem

• In maths, Because of problem #1 + #2= your answer will not match the given options A/B/C/D then you re-calculate the whole sum again=time wasted.
• In reasoning, you’ll take lot of time in each sitting-arrangement/blood-relation / coding-decoding type question. = time wasted

In short, if you want to crack a government / Bank / PSU exam=> aptitude practice@home is essential.

# Maths / Quantitative Aptitude

Donot Fear Maths, Donot Hate Maths. If you basic concepts are clear and you practice enough at home, then most of maths/reasoning questions can be solved without effort or mistake during the exam.

Negative thinking “maths is too difficult, ye mujse nahi hoga”=> you’ll only dig your own grave while others prepare maths and get selected for the job.

For all competitive exams of India, we can classify math topics into following

 Regular topics SSC/CDS/CAT exclusive Misc Topics* prepare for ACIO Ignore for ACIO prepare for ACIO basics (bodmas, surds-indices etc) Number theory, HCF, LCM Algebra, linear equation ratio-proportion-variation average, allegations %, profit loss, SI-CI (interest rate) Time-speed Distance and work (TSDW):includes pipe-cistern, boats streams AVP (Area-volume perimeter) Geometry other than AVP coordinate geometry trigonometry quadratic equations logarithms (Usually non-SSC/CDS/CAT exam don’t bother much asking questions from this topics). PCP (Permutation-Combination-Probability) AP-GP (Arithmetic progression, geometric progression) (Most govt-job exams nowadays don’t bother with these topics but they were asked in ACIO-2012 hence need to be prepared.)

## Preparation Source:

2. Mrunal.org/aptitude
3. Any one Quantitate Aptitude book. Even second hand /used copy will work- you don’t need latest edition. Based on their utility for SSC-CGL exam, I classify the Quant books into 3 types:
 will work in ACIO + Useful for SSC-CGL; CDSBecause quadratic eq., trigonometry and geometry-theory (non-AVP) is covered properly. will work in ACIO but Not so useful for SSC-CGL; CDSBecause quadratic eq., trigonometry and non-AVP geometry is not covered in length. Useless for any exam Readymade Junk from jholachhap publishers like “ACIO guide book; RBI assistant guidebook; National Insurance AO guidebook” etc.
1. For additional practice you may go through previous SSC question papers (but ignore trigonometry, quadratic equation and geometry except Area-volume-perimeter.)

## Permutation combination probability (PCP)

In the late-90s, this used to be the hot-favorite topic for govt.exams, but nowadays rarely comes. However ACIO-2012 did contain two questions from PCP (meaning ACIO paper-setter uncleji still runs with 90s mindset) so you’ve to prepare PCP. Most of the PCP stuff can be solved without any formulas. Go through following articles

And then solve maximum questions from your Quant book.

Observe the questions from 2012’s ACIO paper:

There is a 7-digit telephone number with all different digits. If the digit at extreme right and extreme left are 5 and 6 respectively, find how many such telephone numbers are Possible.

1. 120
2. 1,00,000
3. 6720
4. 30,240

Seven digit phone number looks like this

6*****5

so we’ve five empty seats, and we’ve 8 gentlemen (0,1,2,3,4,7,8,9). Question demand “all different digits” so we can’t use 5 or 6 again. so five seats and eight gentleman. Order/sequencing of number matters. (Because in phone number 1234 is different than phone number 4321). So this is a permutation problem.

= seat1 and seat 2 and …upto seat5

= _ x _ x _ x _ x _ (because in permutation/combination: “and” means multiplication)

= first seat has 8 option x second seat has 7 options x third seat has 6 options..

=8 x 7 x 6 x 5 x 4

# Probability

Probability questions can also be solved with mere extension of Permutation-combination concept. Read the following articles

And then solve maximum questions from your Quant book.

Observe the Question from ACIO 2012:

A speaks the truth 3 out of 4 time, and B speaks truth 5 out of 6 times . What is the probability that they will contradict each other in stating the same fact?

1. 2/3
2. 1/3
3. 5/6
4. 1/21

A speak true=3/4 that means chances of A telling lie =(1- 3/4)=1/4

same way chances of B telling lie=1/6

In probability related question, convert the question into a Statement

Two people will contradict each other, when one speak truth and other is lying

=(A true AND B lie) OR (A lie AND B true)

but in probability, And=multiply (x) and OR=add(+) ;

=(3/4 x 1/6) + (1/4 x 5/6)

=3/24 + 5/24

=8/24

## AP-GP

 arithmetic progression Basics of Arithmetic progression explained in NCERT Class 10 Chap 5. (free downloads @bottom) geometric progression class 11’s NCERT chapter 9.

Then practice sums from your quant-book. AP-GP does require memorizing a few formulas.

Observe the question from ACIO-2012 Exam

After striking the floor, a ball rebounds to 4/5th of the height from which it has fallen, Find the total distance that if travels before coming to rest if it has been gently dropped from a height of 120 metres.

1. 540 meters
2. 960 meters
3. 1080 meters
4. 1120 meters

Ball dropping=geometric progression (GP).

## Approach #1

Distance=height x (1 plus rebounding ratio) / (1 minus rebounding ratio)

Distance

=120 x (1+4/5) / (1-4/5)

=1080 mts

## Approach #2

Distance travelled by ball

=down + {up + down} + {up + down} +… infinite (not infinite in reality though!)

=120 + {4/5(120) + 4/5(120)} + {4/5 [4/5(120)] + 4/5 [4/5(120)]}…upto infinite

=120 + 2 x 4/5(120) + 2 x 4/5 [4/5(120)]… upto infinite

=120 + 2 x 120(4/5 + (4/5)2 + (4/5)3…upto infinite)

but in such infinite GP series highlighted in bold, the summation formula is S=a /(1-r)

therefore sum of bold part

=(4/5)/[1-(4/5)]=4

=120 + (2 x 120 x 4)

=120 + (120 x 8)

=120 x 9

=1080 meters.

Now, Moving to the regular topics:

## Basics (bodmas, surds-indices etc)

In the banking exams, usually first few questions have lengthy multiplication division etc. based on BODMAS. While you don’t need that speed-maths ability for ACIO, but basics should be clear otherwise you’ll make silly calculation mistakes in remaining topics.

 Simplification (BODMAS) NCERT Class 8 Chap 1 Surds, indices NCERT Class 8 Chap 12 Then NCERT Class 9 Chap 1 Roots, squares, Cubes Basics from NCERT Class 8 Chap 6 and 7.

# Algebra, Linear Eq.

“Mother’s age was x and daughters age..”; “3 mangos and 5 bananas purchased for…” ; X+1/2x+3=3/8 then find X.

^This type of stuff. Just practice and you’ll get a hang of it.

1. Basics given in NCERT Class 8 Chap 2 and 9.
2. Then NCERT Class 9 Chap 4
3. Lastly NCERT Class 10 Chap 3.
4. them maximum practice from your quant book

let’s solve ACIO-2012 question

A toy weighing 24 grams of an alloy of two metals is worth Rs 174/-, but if the weights of the two metals be interchanged, the toy would be worth Rs 162/- If the price of one metal be Rs 8 per gram, find the price of the other metal used to make the toy

1. Rs 10/ gram
2. Rs 6/gram
3. Rs 4/ gram
4. Rs 5/gram

Suppose two metals: A and B. A costs 8 rupees and B costs “b” rupees.

## Situation #1

 metal price wt total price A 8 m 8m B b n bn m+n=24 gm (total qty) 8m+bn=174…eq1

## Situation #2

Now we interchange the weights

 metal price wt total price A 8 n 8n B b m bm m+n=24 gm (total qty) 8n+bm=162…eq2

now we’ve two equations

8m+bn=174

8n+bm=162

add left side to left side and right side to right side

(8m+bn)+ (8n+bm)=174+162

Re-arrange

(8m+8n)+(bm+bn)=336

take “8” and “b” common

8(m+n)+b(m+n)=336

but we know that total weight of new alloy is 24gms that means m+n=24

8 x 24 + b x 24=336

24 x (8+b)=336=> you get value of b=6

Ans. price of second metal is Rs.6 per gram

# Average- Allegation

 Wine-Water mixture (Alligations) Can be solved without formula. Go through https://mrunal.org/2012/03/aptitude-alligationsmixturesalloys.html Simple Average complex questions can be made even from simple average. click me to solve them without formulas Ratio-Proportion-variations For ratio-proportion NCERT Class 8 Chap 13. Partnership https://mrunal.org/2012/05/aptitude-partnership-and-profit-sharing.html

# Time speed distance work

This involves

1. Time speed distance
2. Trains, platforms
3. Boats-streams
4. Time and Work
5. Pipes and Cisterns

All of them can be solved with our universal STD formula. see following articles to learn the concept

Then solve max. questions from your quant book

let’s try the question asked in ACIO 2012

1. A man decides to travel 80 kilometers in 8 hours partly by foot and partly on a bicycle. If his speed on foot is 8 km/hr and on bicycle 16 km/hr, what distance would he travel on foot?
1. 20 km
2. 30 km
3. 48 km
4. 60km

Suppose he walked for “t” hours on foot. meaning he spent (8-t) hours on bicycle. (because total time he took is 8 hrs)

Then make an STD table like this:

 on foot on bicycle speed(S) 8 16 time(T) t 8-t distance(D)

STD formula is: speed x time = distance

Apply it in both cases and fillup cells

 on foot on bicycle speed(S) 8 16 time(T) t 8-t distance(D) 8 x t 16 x (8-t)

As per the question we know that total distance he covered was 80kms. Therefore

(distance covered on foot)+(on bicycle)=80

8t+16 (8-t)=80

8t+ (16*8)-16t=80

-8t+ 16*8=80

when you solve this equation you get t=6 hrs. update the table

 on foot on bicycle speed(S) 8 16 time(T) 6 8-t distance(D) 8×6=48kms 16 (8-t)

Ans. He travelled 48 kms on foot.

# Approach #2: Alligiation (Wine Water)

we can also solve this question using alligiation method. How?

first understand the concept explained in following article:

[Aptitude] Alligations,Mixtures,Alloys: Water,Milk,Wine mixing: Weighted Average

let’s check the same ACIO question again

A man decides to travel 80 kilometers in 8 hours partly by foot and partly on a bicycle. If his speed on foot is 8 km/hr and on bicycle 16 km/hr, what distance would he travel on foot?

Since he travelled 80kms n 8 hours, his average speed is

Speed x time = distance

Speed x 8 =80=> avg. speed = 80/8=10

Make the wine-water table:

 concentration (speed) 8 (foot) 10 (avg) 16 (cycle) volume (time) t (8-t)

Apply the visual move, you get two equations: 16-10=t => t=6

10-8=(8-t) =>t=6

In either case t=6

And the distance travelled on foot=> speed x time=8 x 6=48 kms our final answer.

for getting more grip: read following article

# Percentage, profit-loss, SI-CI

All questions whether it is profit-loss-discount-market price ; or simple / compound interest or population increase / decrease=>all of them can be solved without formulas, as long as your basic concept about % is clear. so first understand the concept from following articles

Now let’s try the ACIO 2012 question

Due to a 25 % increase in the price of rice per kilogram a person is able to purchase 20 kilograms less for Rupees 400. What is the increased price of rice per kilogram?

1. Rs 5
2. Rs 6
3. Rs 10
4. Rs 4

this question calls for ‘product consistency’ approach

If rice price increase by 25% then consumption must decrease by…20% (how? let’s see) 25% increase= new price is 125%=5/4

now just inverse it and subtract from 1

1-4/5=1/5

1/5=20%

That means If rice price increase by 25% then consumption must decrease by…20%

But in the question they’re saying “When rice price increased, customer could be 20kg less”

Meaning the decrease of 20kg=20% of the original qty.

Then what was the original qty of rice that customer could buy, before the price rise?

in this question, situation is simple: 20%=20kg then obviously 100%=100kg.

meaning customer was originally buying 100kg rice, for rupees 400. and now he can buy only 100-20=80 kg for 400 rupees.

Therefore, new price of rice per kg =Rs.400/80kg=5 Rs.per kg.

# Number theory, LCM-HCF

 topic approach Divisibility, remainders LCM and HCF Unknown numbers from given conditions Fractions-comparisons. my article explaining the concept of HCF, LCM click me NCERT Class 7 Chap 2, 9 (fraction) NCERT Class 10 Chap 1 (divisibility) Finally practice sums from your Quantitative aptitude book.

let’s check Questions from ACIO 2012

Three bells chime at intervals of 48, 60 and 90 minutes respectively. If all the three bells chime together at 10 AM, at what time will all the three chime again that day

1. 1 PM
2. 2 PM
3. 8 PM
4. 10 PM

This is an LCM question

LCM of (48,60,90)=720 (how to find LCM has been explained in above article)

Meaning they’ll ring after 720 minutes (but we’ve to convert it into hours): 720/60=12hrs

If bells rang together @10AM then they’ll again ring after 12hrs. (Imagine wall clock’s hour hand moving)=after 12 hours the hour hand will again come @10 but it’ll be night= 10PM answer is D

## Finding last two digits

This was also asked in ACIO-2012

1. Find the last two digits of : 15x37x63x51x97x17
1. 35
2. 45
3. 55
4. 85

Make pairs of two number, just focus on last two digits.

15 x 37 =15(30+7)=150+105=last two digits 55

63 x 51=63 (50+1)=3150+63=last two digits 13

97×17=17(90+7)=1530+119=last two digits 49

Now we’ve three new numbers: 55 x (13 x 49)

13 x 49=13 (40+9)=520+117=last two digits 37

now we’ve two numbers

55 x 37 =55 (30+7)=1650 + 385=last two digits 35

# AVP (Area Volume Perimeter)

• Basics explained in NCERT Class 8 Chap 3, 11.Then NCERT Class 9 Chap 9, 12, 13.
• Lastly NCERT Class 10 Chap 13
• in your quant.book you’ll find the consolidated list of formulas and demo questions.

Let’s check the question asked in ACIO2012

A circle is inscribed inside an equilateral triangle touching all the three sides, If the radius of the circle is 2 cm, find the area of the triangle.

1. 15 root 3
2. 18 root 3
3. 12 root 3
4. 12 root 2 In equilateral triangle, if you draw a median, then the center of incircle divides it in 2:1 ratio.=>total length is 3 parts.

Meaning 1 unit =>total length of median will be 1 x 3 =3 unit

We know that radius is 2cm. 2 unit=>total median length will be 2 x 3=>6 units (cm)

Then you run Pythagoras, you get side “a”=(12 / root3) And for equilateral triangles the area is=(root3)/4 x a2
Plug in the value of “a” and you get answer=12 root 3. enough of maths, let’s move to…

# Reasoning

As per ACIO-2012 paper, this portion punning more or less parallel to other exams minus non-verbal ability.
the Recommended Book is as usual: RS Aggarwal’s Modern Approach to verbal and non-verbal reasoning . Then the question is, how to prepare reasoning in systematic manner in the given time?
Do it in following way

# #1: Chart based

• This includes: Direction sense test, Sitting arrangement (rectangle, circular, building, lecture schedules etc.) and blood relations.
• I club them together because in most of them you’ve to make rough diagram / chart / table to solve it. prepare them in following order:
 Sr.No Topic RS Aggarwal Chapter No. 1. Direction Sense Test. 8 2. Sitting arrangement: circular 6 3. Sitting arrangement: rectangle 6 4. Sitting arrangement: “table” based e.g. lecture schedules, job-car-cloth color, building-car-newspaper etc. 6 5. Blood relations 5,6 6 Number ranking time sequence 12 7 arithmetic reasoning 15

# #2: coding n series + alphabet

 Sr.No Topic RS Aggarwal Chapter No. 1. Coding-decoding 4 2 alphabet tests 10 3. Alpha-numeric sequence puzzle 11

# #3 Analogy, odd man

 Sr.No Topic RS Aggarwal Chapter No. 1. Analogy 2 2. Oddmen out 3 (chapter title is “Classification”)

# Non-priority

After you’re done with above topics, if time permits, do following “non-priority” things from RS Agarwal’s

 topic chapter in RS Aggarwal’s reasoning book Input Output 7 Logical venn diagrams 9 Mathematical operations 13 logical sequence of words 14 insert missing characters 16 Data sufficiency 17 Eligibility tests 18 situation-reaction, assertion-reasoning, verification of truth 19 to 21. logical deduction (syllogism etc) section II of his book non-verbal end part of his book

## Reasoning questions asked in ACIO 2012

 coding decoding coding decoding If in a coded language MADRAS is written as LBCSZT, how would BOMBAY be written? APNCBX APLCZZ CPOCBZ CQOCBX If under a certain code the Word CARROM is written as BZQQNL, which word will be Coded as HOUSE GNTRD INVRF IPVTF GPTID sitting arrangement blood relations Five persons A, B, C, D and E are sitting in a row facing you such that D is on the left of C; B is on the right of E; A is on the right of C and B is on the left of D. If E has only one neighbor, then who is sitting in the centre? A B C D A four-person team from Asian Paints is painting Foolan’s house. Mehmood is painting the front of the house. Ramesh is in the alley behind the house painting the back . Jeevan is painting the Window frames on the north side and Sudhir is on the south. If Mehmood switches places With John, and John then switches places with Sudhir, where is Sudhir how? in the alley behind the house on the north side of the house in front of the house on the south side of the house In a family of five persons, Dinesh is Jairam’s son and Gopal’s brother while Meeta is Gopal’s mother and Jayanti’s daughter If there are no step brothers or half brothers in the, family which of the following statements is true? Jayanti is Dinesh’s mother Meeta is Dinesh’s Mother Jayanti is Jairam’s grandmother All the above Rahul’s mother is the only daughter of Monika’s father. How is Monika’s husband related to Rahul’s? Uncle Father Grandfather Brother DBT (Direction Based Test) Puzzle Test ln an exercise, Krishnan walked 25 metres towards South and then he turned to his left and moved, for 20 metres, He again turned to his left and walked 25 metres. Thereafter,he turned to his right and walked 15 metres. What is the distance and direction of his present location with reference to the starting point, 74 metres North East 60 metres North (iii)35 metre East 40 metres South East A man is facing west. He turns 450 in the clockwise direction and then another 1800 in the same direction and then 2700 in the anticlockwise direction. Which direction is he facing now? (i)South -West (ii) South (iii) North-West (iv) West Indira is three times older than Yogesh while Zaheer is half the age of Wahida. If Yogesh is older than Zaheer then Which of the following statements can be inferred ? Yogesh is older than wahida. Indira is older than Wahida. Indira may be younger than Wahida. None of the above four sisters-Suvarna, Tara, Uma and Vihba are playing a game such that the loser doubles the money of each of the other players from her share, They played four games and each sister lost one game in alphabetical order, At the end of fourth game, each sister had Rs.32. How much money did Suvarna start with? Rs 60 Rs 34 Rs 66 Rs 28 calendar sequence-series 1. If it was Saturday on 17th December, 1982 what will be the day on 22nd December, 1984(i) Monday(ii)Tuesday(iii) Wednesday (iv) Sunday 1. One term in the following number series is not correct. 15, 16, 22, 29, 45, 70 Find out the wrong term?(i) 16(ii) 22(iii) 45 (iv) 70

# English

Unlike SSC/IBPS/LIC/CAPF/CDS, here you don’t have to face any grammar, comprehension, vocabulary, idioms or phrases. You just need to write one essay worth 50 marks.

Copy pasting the ACIO-2012 Question paper

Write an essay in English language in only on any one of the following topics is not more than 400 words. (50 marks)

1. India’s Space Programme
2. Causes of corruption in India
3. How to deal with left wing extremism.
• Depending on your font-size/handwriting, 400 words meaning ~4-5 pages (single-side).
• To write a decent essay, what you need is decent points. Essay can be on variety of topics, so ideally you need to keep reading newspapers, magazines, and some good books from library on regular basis. After some months, you have good points on almost every topic.

However: given that not many weeks are left before the ACIO exam- what to do for Essay?

1. IGNOU India democracy and Development zip file. This PDF set contains lot of fodder points to approach most of the social/democracy/Development etc. topics related essays.
2. Topic wise Huge list of essays, from previous UPSC, LIC etc exams.

Fundamental principles remain same like UPSC Essay: spend the first few minutes on brainstorming the idea. Then rank those ideas, start writing essay: introduction >> body (+/- pros, cons) >> conclusion. (click me for more on Essay tips)

Then every day, you try to solve a few essays in your head: Brainstorm for the idea, what will I write in this essay? Can I write 400 words or not- if not then dig books/google for the content.

Also write a few essays on your own every week. (If you don’t have writing practice, then you won’t be able to maintain speed doing the actual exam)

there is no dearth of readymade essay books in the market, but that type of firefighting/desi jugaad, I don’t find it very helpful because such books are either outdated (only reprinted, not updated after 90s), and or don’t cover all the necessary topics. But still, if you want to refer to any books, you may use Spectrum Book of Essays or if you have anyother book- that is also fine. You don’t have to reproduce the same essay verbatim from those books, you can write the essay in your own words- but try to avoid silly grammar/spelling mistakes, write as neatly as possible, without any scratches.

## Essay writing

 for Essay fodder points: IGNOU booklet India Democracy and Development (MPS-003) Click Me for additional Essay practice: big list of mock topics Click Me

The strategy/approach for GA/GK portion of ACIO exam is given in a separate article click me

## 131 Comments on “[Studyplan] ACIO: Aptitude, Maths, Reasoning and English Essay for Assistant Central Intelligence Officer (ACIO) exam”

1. marvellous job… Mrunal sir

2. sir please suggest the essay topics for 2014 acio exam .that will helpful for us…

3. hi sir .Can u keep some essay topics on ib acio plz sir thank uuuu