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civil Maths

Maths : Odd Man Out (Solved in Steps)

1. Find the odd man out. 1, 3, 9, 12, 19, 29

A. 12 B. 9 C. 1 D. 3

Answer : Option A

Explanation :

12 is an even number. All other given
numbers are odd


2. Find the odd man out. 24,36,52,72,96

A. 72 B. 52 C. 36 D. 24

Answer : Option B

Explanation :

All except 52 are multiples of 6


3. Find the odd man out. 1, 8, 27, 64, 125, 196, 216, 343

A. 64 B. 196 C. 216 D. 1

Answer : Option B

Explanation :

The pattern is 1³, 2³, 3³, 4³, 5³, 6³, 7³
196 is not a perfect cube


4. Find the odd man out. 15, 25, 30, 51, 85, 90, 115

A. 15 B. 25 C. 51 D. 90

Answer : Option C

Explanation :

All except 51 are multiples of 5


5. Find the odd man out. 187, 264, 386, 473, 682, 781

A. 386 B. 187 C. 781 D. 682

Answer : Option A

Explanation :

In all numbers except 386, the middle digit is the sum of other two digits.


6. Find the odd man out. 12, 24, 34, 48, 64, 84

A. 48 B. 34 C. 24 D. 12

Answer : Option B

Explanation :

All numbers except 34 are multiples of 4


7. Find the odd man out. 362, 482, 551, 263, 344, 284

A. 362 B. 482 C. 551 D. 344

Answer : Option D

Explanation :

In all numbers except 344, the product of first and third digits is the middle digit.


8. Find the odd man out. 742, 743, 633, 853, 871, 990, 532

A. 532 B. 990 C. 633 D. 742

Answer : Option D

Explanation :

In all numbers except 742, the difference between third and first digit is the middle digit.


9. Find the odd man out. 6, 13, 18, 25, 30, 37, 40

A. 40 B. 30 C. 37 D. 25

Answer : Option A

Explanation :

The difference between two successive terms from the beginning are 7, 5, 7, 5, 7, 5
Hence, in place of 40, the right number is 37+5=42


10. Find the odd man out. 445, 221, 109, 46, 25, 11, 4

A. 25 B. 109 C. 46 D. 221

Answer : Option C

Explanation :

To obtain next number, subtract 3 from the previous number and divide the result by 2
445
(445-3)/2 = 221
(221-3)/2 = 109
(109-3)/2 = 53
(53-3)/2 = 25
(25-3)/2 = 11
(11-3)/2 = 4
Clearly, 53 should have come in place of 46


11. Find the odd man out. 1, 5, 11, 17, 23, 29

A. 29 B. 17 C. 11 D. 1

Answer : Option D

Explanation :

All given numbers except 1 are prime numbers.
One is not a prime number because it does not have two factors. It is divisible by only1


12. Find the odd man out. 2, 3, 5, 9, 12, 17, 23

A. 12 B. 9 C. 23 D. 2

Answer : Option B

Explanation :

2
2 + 1 = 3
3 + 2 = 5
5 + 3 = 8
8 + 4 = 12
12 + 5 = 17
17 + 6 = 23
ie, 8 should have come in place of 9


13. Find the odd man out. 7,13,19,25,29,37,43

A. 19 B. 29 C. 25 D. 43

Answer : Option C

Explanation :

All given numbers except 25 are prime numbers.


14. Find the odd man out. 1, 9, 16, 51, 121, 169, 225

A. 169 B. 51 C. 16 D. 1

Answer : Option B

Explanation :

Each of the given numbers except 51 is a perfect square


15. Find the odd man out. 1, 4, 9, 17, 25, 36, 49

A. 1 B. 9 C. 17 D. 49

Answer : Option C

Explanation :

The patter is 1², 2², 3², 4², 5², 6², 7²
But, instead of 4², 17 is given


16. Find the odd man out. 2, 5, 10, 17, 26, 38, 50, 65

A. 50 B. 38 C. 26 D. 65

Answer : Option B

Explanation :

The pattern is (1×1)+1 , (2×2)+1 , (3×3)+1 ,
(4×4)+1 , (5×5)+1 , (6×6)+1 , (7×7)+1 , (8×8)+1
Hence, in place of 38, the right number was (6×6)+1 = 37


17. Find the odd man out. 18, 16, 12, 24, 11, 34, 46

A. 16 B. 46 C. 16 D. 11

Answer : Option D

Explanation :

11 is the only odd number in the given series


18. Find the odd man out. 1, 27, 216, 512, 1024, 1331

A. 1024 B. 512 C. 27 D. 1

Answer : Option A

Explanation :

All given numbers except 1024 are perfect cubes


19. Find the odd man out. 1, 16, 81, 255, 625, 1296

A. 255 B. 1296 C. 81 D. 1

Answer : Option A

Explanation :

The patter is 1⁴, 2⁴, 3⁴, 5⁴, 6⁴
Hence, in place of 255, the right digit is 4⁴ = 256


20. Find the odd man out. 1050, 510, 242, 106, 46, 16, 3

A. 46 B. 106 C. 510 D. 1050

Answer : Option B

Explanation :

1050
(1050 – 30)/2 = 510
(510 – 26)/2 = 242
(242 – 22)/2 = 110
(110 – 18)/2 = 46
(46- 14)/2 = 16
(16- 10)/2 = 3
Hence, 110 should have come in place of 106


21. Find the odd man out. 3, 8, 18, 38, 78, 158, 316

A. 38 B. 158 C. 316 D. 8

Answer : Option C

Explanation :

3
3 × 2 + 2 = 8
8 × 2 + 2 = 18
18 × 2 + 2 = 38
38 × 2 + 2 = 78
78 × 2 + 2 = 158
158 × 2 + 2 = 318
Hence, 316 is wrong and 318 should have come in place of that


22. Find the odd man out. 5, 6, 14, 45, 185, 925, 5556

A. 5556 B. 925 C. 185 D. 6

Answer : Option C

Explanation :

5 × 1 + 1 = 6
6 × 2 + 2 = 14
14 × 3 + 3 = 45
45 × 4 + 4 = 184
184 × 5 + 5 = 925
925 × 6 + 6 = 5556
Hence, it is clear that 184 should have come instead of 185


23. Find the odd man out. 23, 27, 36, 52, 77, 111, 162

A. 162 B. 111 C. 52 D. 27

Answer : Option B

Explanation :

23+2²=27
27+3²=36
36+4²=52
52+5²=77
77+7²=162
Hence, 113 should have come in place of 111


24. Find the odd man out. 241, 263, 248, 271, 255, 277, 262

A. 277 B. 271 C. 263 D. 241

Answer : Option B

Explanation :

Alternatively, 22 is added and 15 is subtracted from the terms. Hence, 271 is wrong
241
241 + 22 = 263
263 – 15 = 248
248 + 22 = 270
270 – 15 = 255
255 + 22 = 277
277 – 15 = 262


25. Find the odd man out. 125, 127, 130, 135, 142, 153, 165

A. 165 B. 142 C. 153 D. 130

Answer : Option A

Explanation :

Prime numbers 2, 3, 5, 7, 11, 13 are added successively. Hence, 165 is wrong


26. Find the odd man out. 5, 10, 40, 81, 320, 640, 2560

A. 40 B. 81 C. 320 D. 2560

Answer : Option B

Explanation :

Alternatively 2 and 4 are multiplied with the previous terms
5
5 × 2 = 10
10 × 4 = 40
40 × 2 = 80
80 × 4 = 320
320 × 2 = 640
640 × 4 = 2560
Hence, 81 is wrong. 80 should have come in place of 81.


27. Find the odd man out. 12, 21, 32, 45, 60, 77, 95

A. 95 B. 45 C. 32 D. 21

Answer : Option A

Explanation :

12 + 9 = 21
21 + 11 = 32
32 + 13 = 45
45 + 15 = 60
60 + 17 = 77
77 + 19 = 96
Hence, 95 is wrong. 96 should have come in place of 95


28. Find the odd man out. 3, 5, 15, 75, 1120, 84375

A. 84375 B. 1120 C. 15 D. 3

Answer : Option B

Explanation :

Pattern : 1st * 2nd = 3rd, 2nd * 3rd = 4th, etc.
3
5
3 × 5 = 15
5 × 15 = 75
15 × 75 = 1125
75 × 1125 = 84375
Hence, 1120 is wrong. 1125 should have come in place of 1120


29. Find the odd man out. 3576, 1784, 888, 440, 216, 105, 48

A. 105 B. 216 C. 888 D. 1784

Answer : Option A

Explanation :

3576
(3576-8)/2 = 1784
(1784-8)/2 = 888
(888-8)/2 = 440
(440-8)/2 = 216
(216-8)/2 = 104
(104-8)/2 = 48
Hence, 105 is wrong. 104 should have come in place of 105


30. Find the odd man out. 30, -5, -45, -90, -145, -195, -255

A. -5 B. -145 C. -255 D. -195

Answer : Option B

Explanation :

30
30 – 35 = -5
-5 – 40 = -45
-45 – 45 = -90
-90 – 50 = -140
-140 – 55 = -195
-195 – 60 = -255
Hence, -145 is wrong. -140 should have
come in place of -145