Aptitude

Question:
1, 4, 9, 16, 25, 36, 49, (….)

[A].

54

[B].

56

[C].

64

[D].

81

Answer: Option C

Explanation:

Numbers are 12, 22, 32, 42, 52, 62, 72.

So, the next number is 82 = 64.

Question:
5, 10, 13, 26, 29, 58, 61, (….)

[A].

122

[B].

64

[C].

125

[D].

128

Answer: Option A

Explanation:

Numbers are alternatively multiplied by 2 and increased by 3.

So, the missing number = 61 x 2 = 122.

Question:
4, -8, 16, -32, 64, (….)

[A].

128

[B].

-128

[C].

192

[D].

-192

Answer: Option B

Explanation:

Each number is the proceeding number multiplied by -2.

So, the required number is -128.

Question:
125, 127, 130, 135, 142, 153, 165

[A].

130

[B].

142

[C].

153

[D].

165

Answer: Option D

Explanation:

Prime numbers 2, 3, 5, 7, 11, 13 are to be added successively.

So, 165 is wrong.

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.