Series Completion Interview Questions and Answers
Question - 71 : - 6, 15, 35, 77, 165, 221
A. 35
B. 77
C. 165
D. 15
Answer - 71 : -
Option C
Explanation:
The terms of the series are products of two consecutive prime numbers i.e. (2 x 3),
(3 x 5), (5 x 7), (7 x 11),.....
So, 165 is wrong and must be replaced by (11 x 13) i.e. 143.
Question - 72 : - 8, 13, 21, 32, 47, 63, 83
A. 13
B. 21
C. 32
D. 47
Answer - 72 : -
Option D
Explanation:
The correct pattern is + 5, + 8, + 11, + 14,.....
So, 47 is wrong and must be replaced by (32 + 14) i.e. 46.
Question - 73 : - 1, 2, 4, 8, 16, 32, 64, 96
A. 4
B. 32
C. 64
D. 96
Answer - 73 : -
Option D
Explanation:
Each term of the series is obtained by multiplying the preceding term by 2.
So, 96 is wrong and must be replaced by (64 x 2) i.e. 128.
Question - 74 : - 3, 4, 10, 32, 136, 685, 4116
A. 10
B. 32
C. 136
D. 4116
Answer - 74 : -
Option B
Explanation:
The correct pattern is x 1 + 1, x 2 + 2, x 3 + 3, x 4 + 4,.....
So, 32 is wrong and must be replaced by (10 x 3 + 3) i.e. 33.
Question - 75 : - 25, 36, 49, 81, 121, 169, 225
A. 36
B. 49
C. 169
D. 225
Answer - 75 : -
Option A
Explanation:
The correct sequence is 52, 72, 92, 112, 132, 152. So, 36 is wrong.
Question - 76 : - 1, 3, 10, 21, 64, 129, 356, 777
A. 21
B. 129
C. 10
D. 356
Answer - 76 : -
Option D
Explanation:
The correct pattern is x 2 + 1, x 3 + 1, x 2 + 1, x 3 + 1,.....
So, 356 is wrong and must be replaced by (129 x 3 + 1) i.e. 388.
Question - 77 : - 5, 10, 40, 80, 320, 550, 2560
A. 80
B. 320
C. 550
D. 2560
Answer - 77 : -
Option C
Explanation:
The correct pattern is x 2, x 4, x 2, x 4, .....
So, 550 is wrong and must be replaced by (320 x 2) i.e. 640.
Question - 78 : - 2, 3, 4, 4, 6, 8, 9, 12, 16
A. 3
B. 6
C. 9
D. 12
Answer - 78 : -
Option C
Explanation:
The given sequence is a combination of three series:
I. 1st, 4th, 7th terms i.e. 2, 4, 9,.....
II. 2nd, 5th, 8th terms i.e. 3, 6, 12,.....
III. 3rd, 6th, 9th terms i.e. 4, 8, 16,.....
In each one of I, II and III, each term is twice the preceding term. So, 9 is wrong and must be replaced by (4 x 2) i.e. 8.
Question - 79 : - 11, 5, 20, 12, 40, 26, 74, 54
A. 5
B. 20
C. 40
D. 26
Answer - 79 : -
Option C
Explanation:
The given sequence is a combination of two series :
I. 11, 20, 40, 74 and II. 5, 12, 26, 54
The correct pattern in I is + 9, + 18, + 36,.....
So, 40 is wrong and must be replaced by (20 + 18) i.e. 38.
Question - 80 : - 24576, 6144, 1536, 386, 96, 24
A. 96
B. 386
C. 1536
D. 6144
Answer - 80 : -
Option B
Explanation:
Each term of the series is obtained by dividing the preceding term by 4.
So, 1536 is wrong and must be replaced by (1536 + 4) i.e. 384.