[Answerkey] CAPF-2013: Aptitude, Maths, Reasoning, Data interpretation solved with explanation

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  1. Analysis
  2. Aptitude-Internal breakup
  3. Maths
    1. Profit Loss
    2. Basic numeracy/algebra
    3. Ratio
    4. Time-Speed-Distance-Work
    5. Geometry
  4. Data interpretation
  5. Reasoning
    1. Sequence-Series
    2. Coding decoding
    3. Logical Venn Diagram
    4. Clock-Calendar
    5. Non-Verbal

Aptitude-Analysis

  1. Questions not too difficult. Still, if you couldn’t solve all 20 questions accurately, it means (1) you didn’t know the concept/formula/theory (2) you made silly mistake in multiplication/division/addition or subtraction. You can make all excuses about engineer/non-engineer, sci/non-science. But in the end, competition world is cruel, so you’ve to increase practice. The one who runs away from aptitude, usually ends up digging his own grave.
  2. Like last year, they again asked 20 questions from aptitude. Hence weightage/importance of Aptitude hasn’t changed for UPSC CAPF exam.
  3. Last year the pattern was: 13 reasoning and 7 (maths+DI). This year, pattern has reversed: 13 (maths+DI) and 7 reasoning
  4. Like last year, one question on pie chart
  5. Like last year, one question on dice position.
  6. Like last year, one question on clock
  7. unlike last year: no questions from direction sense test or assumption inference.
  8. like SSC CGL, UPSC has also found new attraction for Geometry. Out of 10 maths questions, 4 came from geometry.

Aptitude-Internal breakup

Solved with help of Mr.Deepak Singh and Mr.Manu Jha.

Mathsprofit loss1
basic numeracy/algebra2
Geometry4
ratio-proportion1
time-speed-distance-work2
maths subtotal10
DIData interpretation3
Reasoningsequence-series1
coding-decoding2
logical venn diagram1
clock-calendar1
Non-Verbal2
reasoning subtotal7
totaloverall20

Correction / if you know even faster methods, do share in comments

overall

Polity14Covered. Click me
Geography+EnB+Agro14+8Covered. Click me
Economy+IR+PIN21+4+2Covered. Click me
Science20Click me for Answerkey
History22click me
Aptitude20Given here
total125

Maths

Profit Loss

Q1. selling an article @270, a man loses 10%. If he would sell it @360, his gain percentage is?

  1. 10
  2. 15
  3. 20
  4. 25

He sold @10% lost=90% of cost price, meaning 270 =90% of cost price. Therefore cost price=270/0.9=Rs.300

His cost price is 300 and if he sells at 360 then profit percentage?

=[(360-300)/300] x 100=60/3=20% answer (C)

Alternatively: 360/(270/0.9) =1.20=>100+20 hence profit is 20%

Basic numeracy/algebra

Q1. 9 mangoes cost as much as 5 oranges. 5 oranges cost as much as 3 apples. 4 apples as much as 9 pineapples and if 3 pineapples cost 48. what will a mango cost?

  1. 9
  2. 12
  3. 18
  4. 27

Start from reverse: 3 pineapples = 48 meaning 1 pineapple =48/3=16 Rs.

givenmeaning
4 apple=9 pine1 apple=9P/4
5 orange=3apples1 orange=3A/5=3*9*P/(5*4)=27P/20
9 Mangoes=5 oranges1 mango=5*orange/9=5*27P/(20*9)

but we know that 1 pineapple=16, so,

1 Mango=5*27(16)/(20*9)=>12 Rs. Answer B

Method 2

9 mangoes = 5 oranges =3 apples… (1)

4 apples = 9 pineapples …(2)

3 pineapples = Rs. 48 => 9 pineapples = 48 *3 => 4 apples = 48 *3 (from 2)

1 apple = 12*3 => 3 apples =12*3*3 => 9 mangoes = 12*3*3 ( from 1)

Therefore, 1 mango = Rs. 12 .. option (b)

Method 3

Every fruit’s 1st Alphabet has been taken as variable.

  • 9M = 5O = 3 A
  • 4A=9PA
  • 3PA =Rs 48
  • 1PA = Rs16
  • 9PA = Rs144
  • 4A=Rs 144
  • 3A=Rs 108
  • 9M=Rs 108
  • 1M =Rs12 hence answer (B)

Q2. least integer whose multiplication with 588 leads to perfect square is?

  1. 2
  2. 3
  3. 4
  4. 7

Factors of 588 = 2*2*3*7*7

we already have pairs of twos and pairs of seven. Only three is alone. Hence to make a perfect square, we need to multiply it with 3 =>answer (B)

Ratio

Q1. if the ratio of X:Y=3/4 and ratio of Y:Z=12/13 then ratio of X:Z is

  1. 13/3
  2. 1/3
  3. 4/13
  4. 9/13

Method 1

  • X/Y=3/4, therefore Y=4X/3
  • Y:Z=12/13 (given)
  • replace value of Y
  • (4X/3)/Z=12/13
  • 4X/3Z=12/13
  • X/Z=9/13
  • Hence answer (D)

Method 2

  • x/y = 3/4   …(1)
  • y/z= 12/13 …(2)
  • multiplying equation 1 and 2
  • x/z =  3/4 * 12/13 = 9/13.

Time-Speed-Distance-Work

Q1. If 5 persons can weave 180 mats in 8 days, how many mats can 8 persons weave in 6 days?

  1. 200
  2. 192
  3. 190
  4. 180

Suppose speed of one man is “m”.

situation Asituation B
Speed (S)5m8m
time (T)86
distance (D)=speed x time160=5m*8D=8m*6

Since speed x time = distance.

5m x 8=160=>m=4.

Replace this value in column B’s distance=8m x 6= 8*4*6=192 mats. Answer (B)

Q2. Two cars are moving in the same direction with a speed of 45 km/hr and a distance of 10 km separates them. If a car coming from the opposite direction meets these two cars at an interval of 6 minutes, its speed would be:

  1. 45
  2. 55
  3. 65
  4. 75

Method1: Train concept

Assume the two cars=first and last wagon of one big train. This train is 10km long!

And with respect to this train’s width, the third car is merely a ‘dot’=assume it is a motor cycle.

Rephrasing the question now:

A train of 10km length is moving at a speed of 45kmph. A motorcycle from opposite direction crosses this train in 6 minutes. What is the speed of that motorcycle?

SPEEDsince opposite direction = have to add speeds. Hencefinal speed (S)=speed of train + speed of motorcycle=(45+m)
TIMEtime taken to finish distance(T)=6 minutes=6/60 hours.
DISTANCEDistance=10 kms (the length of train).

apply the STD formula

speed x time = distance

(45+m)*(6/60)=10

m=55 kmph answer (B)

Method #2

  • Car coming from opposite direction meets first car, after 6 minutes it meets second car.
  • In that 6 minutes first car has covered 4.5 km
  • As D=s*t = 45 *6/60= 4.5 km
  • Remaining 5.5 km(10-4.5 = 5.5) covered by  car coming from opposite direction in 6 minutes. Let it’s speed be x km.
  • Therefore,  5.5 = x * 6/60 => x = 55 km/hr..option (b)

Geometry

Q1. find area of the shaded portion

CAPF-2013-Aptitude-Answerkey-circle

  1. 16-4pie
  2. 16-pie
  3. 4-pie
  4. 4-2pie

Observe the smaller square highlighted in purple color.

Size of that smaller square in purple region=one fourth of the big square.

Size of the pie in that purple region=one fourth of the large circle.

therefore, size of the shaded portion

=[small square minus small pie]

=[1/4 (area of big square) minus 1/4 (area of big circle]

=1/4[42-pie*22] ; important: the diameter of big circle=4 hence radius=2.

=1/4[16-4pie]

=[4-pie]

Hence answer (C)

Q2. Sum of the base and altitude of a triangle is 30cm. What is the maximum possible area of such triangle?

  1. 100
  2. 110
  3. 112.5
  4. 120

Area of triangle= 1/2x (base x altitude)

hence area will be maximum when base=altitude

since base + altitude=30cm so for both of them to be equal- they’ve to be 15cm each.

Now for a triangle with b=15cm and h=15cm, the area will be

=1/2 x b x h

=1/2 x (15 x 15)

=112.5 hence answer C

Q3. person walks from O to circular path AB, as shown by arrows. If radius=100 meters then what is the total distance walked (approximately)

CAPF-2013-Aptitude-Answerkey-circle path

  1. 703
  2. 723
  3. 743
  4. 823

The circular path

total degrees=360

he is walking a circle of 360-60 degrees=300 degree.

the circumference of an Arc with 300 degrees

=(300/360)*2pie*radius….eq1

The triangle path

He is walking (OA+OB)…eq2

total distance covered

=eq1+eq2

=(300/360)*2pie*radius+(OA+OB)

=(300/360)*2*3.14*100+(100+100)

=723.33

Hence C is the answer.

Q4. in the following triangle, what is the value of X?

CAPF-2013-Aptitude-Answerkey-exterior angle

  1. 51
  2. 360/7
  3. 62:6/7
  4. 49:4/7

Since 4y is an exterior angle hence

4y=x+2y.

x=2y…eq1

And in a triangle, sum of three angles=180 so,

A+B+C=180

x+2y+3y=180

x+5y=180

2y+5y=180 (from eq1 we know x=2y)

7y=180

y=180/7

plug this value back in eq1

x=2y

x=2*180/7=360/7 hence answer (B)

Data interpretation

Q1. A campus poll covering 300 under-graduate students was conducted in order to study the students’ attitude towards a proposed change in rules for hostel accommodation. The students were required to respond as ‘support’, ‘neutral’ or ‘oppose’ with regard to the issue. Find number for support, neutral and oppose respectively
CAPF-2013-Aptitude-Answerkey-neutral

  1. 150,90,60
  2. 120,100,80
  3. 80,100,120
  4. 60,90,150

shortcut

A circle has total 360 degrees, out of them 96 degrees oppose.

Think in this way – if 96/360 oppose then how many in 300 student oppose?

96/360=Opp/300=>opp=96*300/360=80 students oppose.

So, in the answer (support, neu, opp)= (support,neu,80)

There is only one such pattern- given in Option B. Hence answer B

longcut

so far we found oppose=80. continue finding others

support=144*300/360=120

and finally neutral=total students MINUS (support+oppose)

neutral=300-(80+120)=100

therefore, (support, neu, opp)=120, 100, 80. hence answer (B)

Q2. Expenditure of two families

expensefamily Afamily B
Misc20%70%
Entertainment30%20%
Food50%10%
Monthly Income Rs20,0001 lakh

Correct statement

  1. Family A spends as much on misc. as family B spends on entertainment
  2. The food expense of family B is equal to the total expense of family A
  3. Family A and B spend equally on food
  4. Family A and B spend equally on entertainment

It’ll be better if we just convert percentages into absolute rupees.

expensefamily Afamily B
Misc20%=1/5th of 20k=4k70%=70k
Entertainment30%=3/10th of 20k= 6k20%=20k
Food50%=half of 20k=10k10%=10k
total income20,0001 lakh

now check the statements

  1. Family A spends as much on misc. as family B spends on entertainment
wrong
  1. The food expense of family B is equal to the total expense of family A
wrong
  1. Family A and B spend equally on food
Correct.
  1. Family A and B spend equally on entertainment
wrong

Hence answer (C)

Q3.In a class,40 students passed in Mathematics, 50% of the students passed in English, 5% of the  students failed in Mathematics and English, and 25% of the students passed in both the subjects. What is the ratio of the Number of students passed in English to number of student passed in maths?

  1. 1:1
  2. 2:3
  3. 5:7
  4. 10:9

Total students=40

Failed in both=5% of 40=2=> n=2

passed in both=25% of 40=10

passed in English=50% of 40=20

Construct Venn diagram

CAPF-2013-Aptitude-Answerkey-DI-venn diagram

Those passed only in English=20-10=10 students.

What about those passed only in maths?

=total MINUS (passed only in English + passed in both + failed in Both)

=40-(10+10+2)

=18

so how many passed in MAths?

=passed only in MAths (but failed in English) + passed in both subjects

=18+10=28

Ratio: passed in English : passed in Maths=20:28=5:7. Answer (C)

Reasoning

Sequence-Series

Q1. Find the fifth term in this series: BCYX, EFVU, HISR, KLPO

  1. NOML
  2. NOLM
  3. ONML
  4. ONLM

Pattern: each term is made of two blocks, observe

BC||YXBC (move forward by one alphabet)=+D=EFYX (move backward by one alphabet)=-W=UV and flip it=VUresult is second term EF||VU

On the same pattern

KL||PO

KL + move forward by one alphabet (M)=NO

PO+ move backward by one alphabet (N)=LM and flip it=ML

Hence fifth term will be NO||ML=>answer (A)

Coding decoding

Q1. In a certain code, ‘PLANT’ is written as [email protected]*c and Yield is written as [email protected]%. What is the code for Delay?

  1. b4*2%
  2. [email protected]%
  3. %[email protected]
  4. %[email protected]
PLANT
$@2*c

and

YIELD
b64@%

plug in the values for Delay, using above chart.

DELAY
%4@2b

Hence answer (D)

Q2. A is coded as 1, B as 3, C as 5 and  so on. Which of the following is the numerical value of the word ‘FAZED’ if the numerical value of CABLE is 41?

  1. 81
  2. 80
  3. 79
  4. 77

A= 1 , B= 3 , C = 5.

It is an Arithmetic progression with common difference 2.

hence pattern is a+(n-1)*d

let’s make table only for the alphabets we need

A1
B3
C5
D7
E9
F11
L12th term=1+(12-1)*2=23
Z26th term=1+(26-1)*2=51

now let’s check

CABLE

=C+A+B+L+E

=5+1+3+23+9=41 (correct match to question condition.)

now FAZED

=F+A+Z+E+D

=11+1+51+9+7=79 hence answer (C)

Logical Venn Diagram

Q1. Which one among the following diagrams illustrates relationship among animals, cows and horses?

CAPF-2013-Aptitude-Answerkey-venn-animals-cows

Animals (cows, horses)..  option (c)

Clock-Calendar

Q1. through how many degrees does the hour hand in a clock move as the time changes from 3 hours and 12 minutes to 6 hours?

  1. 105
  2. 99
  3. 90
  4. 84

shortcut

Hour hand is the shorter hand. If it moved from 3PM to 6PM, we can say 90 degrees. Hence at 3.12 minutes to 6PM, it’ll be less than 90 degrees. There is only one option (D) qualifies under this condition, because 84 is less than 90.

Longcut#1 (using hour distance)

Circle has total 360 degrees and a clock has markings for total 12 hours. Therefore, one hour=360/12=30 degrees.

approach 1approach 2
  • 12 to 6=half the circle=180 degreess…eq1
  • 12 noon to 3:12PM=3 hours and 12 minutes
  • =3 (30) + (12/60)*30
  • =96 degrees…eq2

now the distance between 3:12 and 6=eq1 minus eq2=180-96=84 degrees. Option D

  • from 3:12 to 6PM, time remaining is 2 hours and 48 minutes.
  • and 48 minutes=48/60 hours.
  • distance (2h48m)=(2*30)+(48/60)*30
  • =84 degrees

Longcut#2 (using minute distance)

  • in a clock, 3 hours=90 degree and 3 hour=3 x 60 minutes=180 minutes
  • therefore, 180 minutes=90 degree=>1 minute =90/180=0.5degree.
  • from 3.12PM to 6PM, total minutes are 2 hours + 48 minutes=168 min (from 3 hr 12 mins to 6 hrs = 180 – 12 mins)  168 min = how many degrees ? 168*0.5=84 degree. Hence answer (D)

Non-Verbal

Q1. what will be the next figure in this series?

CAPF-2013-Aptitude-Answerkey-non-verbal-series

Black dot is moving from corner to corner. Plus sign and white dot are moving cross to and fro. Whenever two signs coincide it becomes black dot. ..option (a)

Q2. Which one among the following boxes is similar to the box formed from the given sheet of paper (X)?

CAPF-2013-Aptitude-Answerkey-non-verbal-dice

method1

F & B cant be adjacent sides. A ruled out.

D & A  cant be adjacent sides. D ruled out.

E & C are opposite sides , Hence C ruled out.

Hence we’re left with answer (B)

method2

Visualizing the box B,E,F,C are on the same straight line and A,D forms the opposite sides of visualized box. Therefore one possible combination with respective opposite faces is

B <->F, E<->C , A<->D=option (b)

Correction / if you know even faster methods, do share in comments
Courtesy: Mr.Deepak Singh and Mr.Manu Jha for providing valuable inputs.

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57 Comments on “[Answerkey] CAPF-2013: Aptitude, Maths, Reasoning, Data interpretation solved with explanation”

  1. Brother it misplacing in mat . in question there is 180

    And in solutions. It’s 160

    So that correct as per answer given is 192
    So 160 is correct

  2. In a class consisting of 100 students 20 know English and 20 do not know Hindi and 10 know neither English nor Hindi. The number of students knowing both Hindi and English is

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