Practice MCQ Questions and Answer on Number Series Completion
41.
44, 41, 38, 35, 32, 29, 26, ... choose which pair of numbers comes next?
(A) 24, 21
(B) 22, 19
(C) 23, 19
(D) 29, 32
Solution:
Answer & Solution Answer: Option E Solution: This is a simple subtraction series, in which 3 is subtracted from each number to arrive at the next.
42.
72, 76, 73, 77, 74, __, 75. What number should fill the blank?
(A) 70
(B) 71
(C) 75
(D) 78
Solution:
This series alternates the addition of 4 with the subtraction of 3.
43.
8, 11, 21, 15, 18, 21, 22, ... choose which pair of numbers comes next?
(A) 25, 18
(B) 25, 21
(C) 25, 29
(D) 24, 21
Solution:
This is an alternating addition series, with a random number, 21, interpolated as every third number. The addition series alternates between adding 3 and adding 4. The number 21 appears after each number arrived at by adding 3.
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
45.
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.
46.
Find out the wrong term: 125, 126, 124, 127, 123, 129
(A) 126
(B) 124
(C) 123
(D) 129
Solution:
The correct pattern is + 1, - 2, + 3, - 4, + 5.So, 129 is wrong and must be replaced by (123 + 5) i.e., 128
47.
Find the missing term: 125, 80, 45, 20, ?
(A) 5
(B) 8
(C) 10
(D) 12
Solution:
The pattern is - 45, - 35, - 25,........ So, missing term = 20 - 15 = 5
48.
Which of the following will not be a number of the series 1, 8, 27, 64, 125, ....?
(A) 256
(B) 512
(C) 729
(D) 1000
Solution:
The given series consists of cubes of natural numbers only. 256 is not the cube of any natural number.
49.
14, 28, 20, 40, 32, 64, ... What number should come next?
(A) 52
(B) 56
(C) 96
(D) 128
Solution:
This is an alternating multiplication and subtracting series: First, multiply by 2 and then subtract 8.
50.
1, 10, 7, 20, 13, 30, 19, ... choose which pair of numbers comes next?
(A) 26, 40
(B) 29, 36
(C) 40, 25
(D) 25, 31
Solution:
Here, every other number follows a different pattern. In the first series, 6 is added to each number to arrive at the next. In the second series, 10 is added to each number to arrive at the next.