Odd Man Out and Series problems test one’s ability to discern patterns and sequences in numbers, letters, or symbols. These problems require identifying the underlying rule in a series or finding which element does not fit a certain pattern. They are common in various competitive exams and are key in assessing logical reasoning and analytical skills.

## 1. Find the odd one out: 3, 5, 11, 14, 17, 19

a) 3

b) 11

c) 14

d) 17

### Answer:

c) 14

### Explanation:

```
All except 14 are prime numbers.
```

## 2. Choose the number that does not belong: 64, 125, 216, 312, 729

a) 125

b) 216

c) 312

d) 729

### Answer:

c) 312

### Explanation:

```
All except 312 are perfect cubes (4^3, 5^3, 6^3, 9^3). 312 is not a perfect cube.
```

## 3. Find the odd one out: 2, 6, 12, 20, 30, 42, 56

a) 12

b) 20

c) 30

d) 42

### Answer:

c) 30

### Explanation:

```
All others are products of two consecutive numbers (2×1, 3×2, 4×3, 6×5, 7×6). 30 is not.
```

## 4. Select the odd one: ACD, EGJ, IKN, MPR, SVY

a) ACD

b) EGJ

c) MPR

d) SVY

### Answer:

c) MPR

### Explanation:

```
In all others, the second and third letters are consecutive in the alphabet.
```

## 5. Identify the odd series: 1, 4, 9, 16, 25, 36; 2, 3, 5, 8, 12, 17; 3, 5, 8, 12, 17, 23; 4, 7, 11, 16, 22, 29

a) 1, 4, 9, 16, 25, 36

b) 2, 3, 5, 8, 12, 17

c) 3, 5, 8, 12, 17, 23

d) 4, 7, 11, 16, 22, 29

### Answer:

a) 1, 4, 9, 16, 25, 36

### Explanation:

```
All in option a) are perfect squares. The others are not.
```

## 6. Choose the odd one out: 41, 43, 47, 53, 61

a) 41

b) 43

c) 53

d) 61

### Answer:

d) 61

### Explanation:

```
All except 61 are prime numbers less than 50.
```

## 7. Identify the odd series: ABC, DEF, GHI, JKL, MNO, QRS

a) ABC

b) DEF

c) JKL

d) QRS

### Answer:

d) QRS

### Explanation:

```
All others are sequences of three consecutive alphabets. QRS skips P.
```

## 8. Find the odd one out: 121, 144, 169, 196, 225, 256, 289

a) 144

b) 169

c) 196

d) 256

### Answer:

d) 256

### Explanation:

```
All except 256 are odd perfect squares. 256 is an even perfect square (16^2).
```

## 9. Choose the odd one: 8, 27, 64, 100, 125

a) 27

b) 64

c) 100

d) 125

### Answer:

c) 100

### Explanation:

```
All except 100 are perfect cubes.
```

## 10. Identify the odd series: 6-18, 10-30, 14-42, 18-54, 22-66

a) 6-18

b) 10-30

c) 14-42

d) 22-66

### Answer:

d) 22-66

### Explanation:

```
In all others, the second number is three times the first. In 22-66, it is not.
```

## 11. Find the odd one out: 7, 14, 28, 35, 49

a) 7

b) 14

c) 28

d) 35

### Answer:

d) 35

### Explanation:

```
All except 35 are multiples of 7 and less than 30.
```

## 12. Select the odd one: 3, 8, 15, 24, 35, 48

a) 8

b) 15

c) 24

d) 35

### Answer:

d) 35

### Explanation:

```
All others are one less than a perfect square.
```

## 13. Identify the odd series: 579, 264, 863, 642, 461

a) 579

b) 264

c) 863

d) 642

### Answer:

c) 863

### Explanation:

```
In all others, the middle digit is the sum of the other two.
```

## 14. Choose the odd one out: 1/3, 2/5, 3/7, 4/9, 5/11

a) 1/3

b) 2/5

c) 3/7

d) 4/9

### Answer:

d) 4/9

### Explanation:

```
All others are fractions where the denominator is two more than the numerator.
```

## 15. Find the odd one out: 0, 5, 10, 15, 20, 25, 30

a) 0

b) 10

c) 20

d) 25

### Answer:

d) 25

### Explanation:

```
All except 25 are multiples of 5 and less than or equal to 30.
```

## 16. Select the odd one: AEG, BFI, CHK, DJL, EKN

a) AEG

b) BFI

c) CHK

d) EKN

### Answer:

d) EKN

### Explanation:

```
In all others, the second and third letters are consecutive in the alphabet.
```

## 17. Identify the odd series: 1-3, 4-12, 6-18, 8-24, 10-30

a) 1-3

b) 4-12

c) 6-18

d) 10-30

### Answer:

b) 4-12

### Explanation:

```
In all others, the second number is three times the first. In 4-12, it is not.
```

## 18. Choose the odd one out: 31, 37, 41, 43, 53

a) 31

b) 37

c) 41

d) 53

### Answer:

a) 31

### Explanation:

```
All except 31 are prime numbers greater than 30.
```

## 19. Find the odd one out: 6, 12, 18, 24, 30, 36, 45

a) 12

b) 18

c) 30

d) 45

### Answer:

d) 45

### Explanation:

```
All others are multiples of 6.
```

## 20. Select the odd one: 121, 131, 141, 151, 161

a) 121

b) 131

c) 141

d) 161

### Answer:

c) 141

### Explanation:

```
All others are prime numbers.
```

## 21. Identify the odd series: 1357, 2468, 3579, 4680, 5791

a) 1357

b) 2468

c) 3579

d) 4680

### Answer:

d) 4680

### Explanation:

```
In all others, each digit is one more than the previous digit.
```

## 22. Choose the odd one out: 16, 25, 36, 49, 64

a) 16

b) 25

c) 36

d) 49

### Answer:

a) 16

### Explanation:

```
All except 16 are odd perfect squares.
```

## 23. Find the odd one out: 2-10, 3-15, 4-20, 5-25, 6-30

a) 2-10

b) 3-15

c) 4-20

d) 5-25

### Answer:

d) 5-25

### Explanation:

```
In all others, the second number is five times the first.
```

## 24. Select the odd one: CAT, BAT, RAT, MAT, PAT

a) CAT

b) BAT

c) RAT

d) MAT

### Answer:

d) MAT

### Explanation:

```
All others have animals' names.
```

## 25. Select the odd one: CAT, BAT, RAT, MAT, PAT

a) CAT

b) BAT

c) RAT

d) MAT

### Answer:

d) MAT

### Explanation:

```
All others represent names of animals, whereas MAT does not.
```

## 26. Identify the odd series: 1-4-9, 2-8-18, 3-12-27, 4-16-36, 5-20-45

a) 1-4-9

b) 2-8-18

c) 4-16-36

d) 5-20-45

### Answer:

b) 2-8-18

### Explanation:

```
In all series except 2-8-18, the third number is the square of the first number (1^2 = 1, 3^2 = 9, 4^2 = 16, 5^2 = 25). In 2-8-18, 18 is not the square of 2.
```