Odd Man Out and Series

Question:
4, 6, 8, 9, 10, 11, 12

[A].

10

[B].

11

[C].

12

[D].

9

Answer: Option B

Explanation:

Each number is a composite number except 11.

Question:
105, 85, 60, 30, 0, -45, -90

[A].

0

[B].

85

[C].

-45

[D].

60

Answer: Option A

Explanation:

Subtract 20, 25, 30, 35, 40, 45 from successive numbers.

So, 0 is wrong.

Question:
52, 51, 48, 43, 34, 27, 16

[A].

27

[B].

34

[C].

43

[D].

48

Answer: Option B

Explanation:

Subtract 1, 3, 5, 7, 9, 11 from successive numbers.

So, 34 is wrong.

Question: 1, 2, 6, 15, 31, 56, 91

[A].

31

[B].

91

[C].

56

[D].

15

Answer: Option B

Explanation:

1, 1 + 12 = 2, 2 + 22 = 6, 6 + 32 = 15, 15 + 42 = 31, 31 + 52 = 56, 56 + 62 = 92

Last number of given series must be 92 not 91.

Question:
25, 36, 49, 81, 121, 169, 225

[A].

36

[B].

49

[C].

121

[D].

169

Answer: Option A

Explanation:

The numbers are squares of odd natural numbers, starting from 5 up to 15.

So, 36 is wrong.

Question:
8, 13, 21, 32, 47, 63, 83

[A].

47

[B].

63

[C].

32

[D].

83

Answer: Option A

Explanation:

Go on adding 5, 8, 11, 14, 17, 20.

So, the number 47 is wrong and must be replaced by 46.

Question: 56, 72, 90, 110, 132, 150
[A].

72

[B].

110

[C].

132

[D].

150

Answer: Option D

Explanation:

The numbers are 7 x 8, 8 x 9, 9 x 10, 10 x 11, 11 x 12, 12 x 13.

So, 150 is wrong.

Question:
6, 13, 18, 25, 30, 37, 40

[A].

25

[B].

30

[C].

37

[D].

40

Answer: Option D

Explanation:

The differences between two successive terms from the beginning are 7, 5, 7, 5, 7, 5.

So, 40 is wrong.

Question:
5, 16, 6, 16, 7, 16, 9

[A].

9

[B].

7

[C].

6

[D].

None of these

Answer: Option A

Explanation:

Terms at odd places are 5, 6, 7, 8 etc. and each term at even place is 16.

So, 9 is wrong.

Question:
1, 8, 27, 64, 124, 216, 343

[A].

8

[B].

27

[C].

64

[D].

124

Answer: Option D

Explanation:

The numbers are 13, 23, 33, 43 etc. So, 124 is wrong; it must have been 53i.e., 125.