Series Completion Interview Questions and Answers
Question - 1 : - 120, 99, 80, 63, 48, ?
A. 35
B. 38
C. 39
D. 40
Answer - 1 : -
Option A
Explanation:
The pattern is - 21, - 19, - 17, - 15,.....
So, missing term = 48 - 13 = 35.
Question - 2 : - 589654237, 89654237, 8965423, 965423, ?
A. 58965
B. 65423
C. 89654
D. 96542
Answer - 2 : -
Option D
Explanation:
The digits are removed one by one from the beginning and the end in order alternately
so as to obtain the subsequent terms of the series.
Question - 3 : - 3, 10, 101,?
A. 10101
B. 10201
C. 10202
D. 11012
Answer - 3 : -
Option C
Explanation:
Each term in the series is obtained by adding 1 to the square of the preceding term.
So, missing term = (101)^{2} + 1 = 10202.
Question - 4 : - In the series 2, 6, 18, 54, ...... what will be the 8th term ?
A. 4370
B. 4374
C. 7443
D. 7434
Answer - 4 : -
Option B
Explanation:
Clearly, 2 x 3 = 6, 6 x 3 = 18, 18 x 3 = 54,.....
So, the series is a G.P. in which a = 2, r = 3.
Therefore 8th term = ar^{8-1 }= ar^{7} = 2 x 3^{7} = (2 x 2187) = 4374.
Question - 5 : - 125,80,45,20,?
A. 5
B. 8
C. 10
D. 12
Answer - 5 : -
Option A
Explanation:
The pattern is - 45, - 35, - 25, .....
So, missing term = 20 - 15 = 5.
Question - 6 : - 13, 32, 24, 43, 35, ?, 46, 65, 57, 76
A. 45
B. 52
C. 54
D. 55
Answer - 6 : -
Option C
Explanation:
The given sequence is a combination of two series:
I. 13, 24, 35, 46, 57 and II. 32, 43, ?, 65, 76
The pattern in both I and II is + 11. So, missing term = 43 + 11 = 54.
Question - 7 : - 22, 24, 28, ?, 52, 84
A. 36
B. 38
C. 42
D. 46
Answer - 7 : -
Option A
Explanation:
The pattern is + 2, + 4, + 8, + 16,.....
So, missing term = 28 + 8 = 36.
Question - 8 : - 3, 15, ?, 63, 99, 143
A. 27
B. 35
C. 45
D. 56
Answer - 8 : -
Option B
Explanation:
The terms of the given series are (2^{2} - 1), (4^{2} - 1),....., (8^{2 }- 1), (10^{2} - 1), (12^{2 }- 1).
So, missing term = (6^{2} - 1) - (36 - 1) = 35.
Question - 9 : - 90, 180, 12, 50, 100, 200, ?, 3, 50, 4, 25, 2, 6, 30, 3
A. 150
B. 175
C. 225
D. 250
Answer - 9 : -
Option A
Explanation:
Clearly, 90 = 30 x 3, 180 = 6 x 30, 12 = 2 x 6, 50 = 25 x 2, 100 = 4 x 25, 200 = 50 x 4.
So, missing term = 3 x 50 = 150.
Question - 10 : - 48, 24, 96, 48, 192, ?
A. 76
B. 90
C. 96
D. 98
Answer - 10 : -
Option C
Explanation:
The pattern is ÷ 2, x 4, ÷ 2, x 4, .....
So, missing term = 192 ÷ 2 = 96.