Practice MCQ Questions and Answer on Number Series Completion
161.
21, 25, 18, 29, 33, 18, ... choose which pair of numbers comes next?
(A) 43, 18
(B) 41, 44
(C) 37, 18
(D) 37, 41
Solution:
This is a simple addition series with a random number, 18, interpolated as every third number. In the series, 4 is added to each number except 18, to arrive at the next number.
162.
Find the missing term: 3, 10, 101, ?
(A) 10101
(B) 10201
(C) 10202
(D) 11012
Solution:
Each term in the series is obtained by adding 1 to the square of the preceding term.So, missing term = (101)2 + 1 = 10202
163.
Find the missing term : 5, 16, 51, 158, ?
(A) 1452
(B) 483
(C) 481
(D) 1454
Solution:
The series is as follows:5 × 3 + 1 = 1616 × 3 + 3 = 5151 × 3 + 5 = 158158 × 3 + 7= 481
164.
In the following number series a wrong number is given. Find out the wrong number.
150, 450, 750, 1060,1350,1650,1950
(A) 1060
(B) 1950
(C) 450
(D) 1350
Solution:
By adding 300 to each term, we get the next term. 1060 is wrong term. It should be 1050.
165.
21, 9, 21, 11, 21, 13, 21, ... What number should come next?
(A) 14
(B) 15
(C) 21
(D) 23
Solution:
In this alternating repetition series, the random number 21 is interpolated every other number into an otherwise simple addition series that increases by 2, beginning with the number 9.
166.
70, 71, 76, __, 81, 86, 70, 91. What number should fill the blank?
(A) 70
(B) 71
(C) 80
(D) 96
Solution:
In this series, 5 is added to the previous number; the number 70 is inserted as every third number.
167.
58, 52, 46, 40, 34, ... What number should come next?
(A) 26
(B) 28
(C) 30
(D) 32
Solution:
This is a simple subtraction series. Each number is 6 less than the previous number.
168.
Find out the wrong term: 445, 221, 109, 46, 25, 11, 4
(A) 25
(B) 46
(C) 109
(D) 221
Solution:
3 is subtracted from each number and the result divided by 2 to obtain the next number of the series,So, 46 is wrong and must be replaced by (109 - 3)/2 i.e., 53.
169.
Find the missing term :- 3, 15, ?, 63, 99, 143
(A) 27
(B) 35
(C) 45
(D) 56
Solution:
The terms of the given series are (22 - 1), (42 - 1),................,(82 - 1), (102 - 1), (122 - 1)So, missing term = (62 - 1) = (36 - 1) = 35
Let the missing terms of the series be x1 and x2.Thus, the sequence 20, 20, 19, 16, 17, 13, 14, 11. x1, x2 is a combination of two series:I. 20, 19, 17, 14, x1 and II. 20, 16, 13, 11, x2The pattern in I is - 1, - 2, - 3,..............So, missing term, x1= 14 - 4 = 10The pattern in II is - 4, - 3, - 2,.......... So,missing term, x2 = 11 - 1 = 10