QUESTIONS ON REASONING (PART-6)

Most of these questions are taken from the previous examinations conducted by the Staff Selection Commission (SSC) of the General Intelligence and Reasoning section of the following exams as well as other similar exams. They are all solved and supported by detailed explanation.

1. Combined Graduate Level (CGL) Exam Tier-I

2. Combined Higher Secondary (10+2) Exam (CHSL) Tier-I

3. SI in Delhi Police and CPO Exam Tier-I

4. Stenographers Exam

5. Grade-II DASS Exam conducted by Delhi Staff Subordinate Services (DSSSB)

QUERY 101

Find wrong number
9, 19, 40, 83, 170, 340

40
83
170
340

Krishna Singh Thakur
9*2 + 1 = 19
19*2 + 2 = 40
40*2 + 3 = 83
83*2 + 4 = 170
170*2 + 5 = 345

So the wrong number is 340 (option ‘4’)

QUERY 102

Find wrong number in 0, 7, 28, 63, 124, 215

7
215
63
28

MAHA GUPTA
Careful examination will say that every number is subtraction of 1 from cube of a natural number starting from 1; see how

0 = 1^3 – 1
7 = 2^3 – 1

So the next number must be 26 in place of 28 (option ‘4’)
26 = 3^3 – 1

63 = 4^3 – 1
124 = 5^3 – 1
215 = 6^3 – 1

QUERY 103

Find wrong number
5, 13, 29, 61, 120, 253

61
253
29
120

MAHA GUPTA
Every number in the series is addition of 3 to double of its previous; see how
5*2 + 3 = 13
13*2 + 3 = 29
29*2 + 3 = 61

so the next number = 61*2 + 3 = 125; not 120 (option ‘4’)
125*2 + 3 = 253

QUERY 104

13 : 19 : : 21 : ?

141
14
81
41

MAHA GUPTA
LHS
First and second digits of the second numbers are squares of the first and second digits of the first number respectively; see how
1^2 = 1
3^2 = 9

Therefore the desired number of RHS
2^2 = 4
1^2 = 1
Means 41 (option ‘4’)

QUERY 105

Find odd number
27, 125, 216, 343

216
343
125
27

MAHA GUPTA
27 (option ‘4’). The other numbers are cubes of consecutive numbers, whereas 27 not.

QUERY 106

6 : 64 : : 11 : ?

144
169
121
124

MAHA GUPTA
The second number on each side is the square of 2+the first number; see how
LHS
64 = (2+6)^2 = 8^2

So the required number = (2+11)^2 = 13^2 = 169 (option ‘2’)

QUERY 107

If 55 + 66 = 33 , 22 + 99 = 33; then
44 + 88 = ?

38
40
33
36

MAHA GUPTA
Number on RHS is three times of the sum of one of the digits of each number on LHS; see how
(5+6)*3 = 33
(2+9)*3 = 33

Hence the required number = (4+8)*3 = 36 (option ‘4’)

QUERY 108

If LONG is IG; what will be NAIL?

MAHA GUPTA
L = 12; O = 15. Hence L+O = 27; 27/3 = 9 = I
N = 14; G = 7. Hence N+G = 21; 21/3 = 7 = G
So LONG = IG

Now N = 14; A = 1. Hence N+A = 15; 15/3 = 5 = E
I = 9; L = 12. Hence I+L = 21; 21/3 = 7 = G
So NAIL = EG (answer)

QUERY 109

MAHA GUPTA

Multiply the number of the outer triangle by its predecessor and 3 to get the number of the adjacent triangle; see how
2*1 + 3 = 5
3*2 + 3 = 9
4*3 + 3 = 15
5*4 + 3 = 23 (answer)
6*5 + 3 = 33
7*6 + 3 = 45

QUERY 110

2 * 2 = 44
4 * 4 = 168
6 * 6 = 3612
9 * 9 = ?

MAHA GUPTA
First square the digit of LHS and then add to get RHS; see how
2^2 = 4; 2+2 = 4. RHS = 44
4^2 = 16; 4+4 = 8. RHS = 168
6^2 = 36, 6+6 = 12. RHS = 3612

Therefore the required number
9^2 = 81, 9+9 = 18. RHS = 8118

QUERY 111

Find missing number
8       9       10
5       4        3
28     ?       16
12    25      14

 

Deepak Sharma
Column-I: 8*5 – 12 = 28
Column-III: 10*3 – 14 = 16

Therefore, Column-II: 9*4 – 25 = 11 (answer)

QUERY 112

MAHA GUPTA

TYRE : BICYCLE. PETAL is a part of a flower that can be separated intact; likewise TYRE is a part of a bicycle that can be separated intact. SALT though can be a part of pepper, but can’t be separated from it.

QUERY 113

1, 3, 8, 19, 42, ?

65
71
89
93

MAHA GUPTA
Every number in the sequence is addition of a number in ascending order to its preceding number in sequence 1st, 2nd, 3rd, 4th; see how
1st number after 1 is 2; 1+2 = 3
2nd number after 3 is 5; 3 +5 = 8
3rd number after 8 is 11; 8+11 = 19
4th number after 19 is 23;19+23 = 42

Hence the required number
5th number after 42 is 47; 42+47 = 89 (option ‘3’)

QUERY 114

Karan Mehta
Can’t be energy and power because of irrelevant relationship; can’t be cells as its number can vary in a battery.

TERMINALS (option ‘C’) is right option as there are two two poles in a magnet.

QUERY 115

IC : 6 :: DP : ??

14
10
12
16

MAHA GUPTA
I = 9; C = 3
2nd term of LHS = (9+3)/2 = 6

D= 4; P = 16
Therefore the 2nd term of RHS = (4+16)/2 = 10 (option ‘2’)

QUERY 116

MAHA GUPTA

One should take these things in general; to think what happens generally at top level will lead us to wrong estimation for sure. All these three categories of people may be intermixed no doubt. So only and only answer is option ‘2’.

QUERY 117

MAHA GUPTA

Option ‘B’. One should take these things in general; to think what happens generally at top level will lead us to wrong estimation for sure. All these three categories of people may be intermixed no doubt. So only and only answer is option ‘B’.

QUERY 118

MAHA GUPTA

Option ‘1’. The middle circle represents ANTIBIOTICS. A capsule can contain an antibiotics inside or not, likewise an injection too can be of an antibiotics or not. But a capsule and injection are entirely two different things.

QUERY 119

120, 440, 960, 1680, ?

2600
3240
3040
2400

MAHA GUPTA
The difference in two consecutive number is increasing by 200; see how
440 – 120 = 320
960 – 440 = 520
1680 – 960 = 720

So the required number = 1680 + 920 = 2600 (option ‘1’)

QUERY 120

Find the odd word
wave
current
tide
storm

MAHA GUPTA
TIDE (option ‘3’). TIDE is a regular rise and fall in the level of sea caused by the pull of the moon and sun, whereas cause of all the other things mentioned is different.