Practice MCQ Questions and Answer on Number Series Completion
201.
Find the missing term: 1, 1, 4, 8, 9, 27, 16, ?
(A) 32
(B) 64
(C) 81
(D) 256
Solution:
The series consists of squares and cubes of consecutive natural numbers i.e., 12 , 13, 22 , 23 , 32 , 33 , 42 .................So, missing term = 43 = 64
202.
42, 40, 38, 35, 33, 31, 28, ... choose which pair of numbers comes next?
(A) 25, 22
(B) 26, 23
(C) 26, 24
(D) 25, 23
Solution:
This is an alternating subtraction series in which 2 is subtracted twice, then 3 is subtracted once, then 2 is subtracted twice, and so on.
203.
Find the missing term: 625, 5, 125, 25, 25, ?, 5
(A) 5
(B) 25
(C) 125
(D) 625
Solution:
The given sequence is a combination of two series:I. 625, 125, 25, 5 andII. 5, 25, ?The pattern is ÷ 5, while that in II is × 5.So, missing term = 25 × 5 = 125
204.
In a given series one term is wrong or missing term: 1, 2, 5, 10, 17, 28
(A) 30
(B) 28
(C) 27
(D) 17
Solution:
The correct sequence is + 1, + 3, + 5, + 7, + 9.So, 28 is wrong and must be replaced by (17 + 9) i.e., 26.
The given sequence is a combination of two series:I. 3, 7, 13, 21, 31, ? andII. 4, 7, 13, 22, 34The pattern in I is + 4, + 6, + 8, + 10,......The pattern in II is + 3, + 6, + 9, + 12,..............So, missing term = 31 + 12 = 43
206.
VI, 10, V, 11, __, 12, III. What number should fill the blank?
(A) II
(B) IV
(C) IX
(D) 14
Solution:
This is an alternating addition and subtraction series. Roman numbers alternate with Arabic numbers. In the Roman numeral pattern, each number decreases by 1. In the Arabic numeral pattern, each number increases by 1.
207.
Find the missing term: 48, 24, 96, 48, 192, ?
(A) 76
(B) 90
(C) 96
(D) 98
Solution:
The pattern is ÷ 2, × 4, ÷ 2, × 4,........... So, missing term = 192 ÷ 2 = 96
208.
Find out the wrong term: 5, 27, 61, 122, 213, 340, 509
(A) 27
(B) 61
(C) 122
(D) 509
Solution:
We have :I: 5 27 61 122 213 340 509II: 22 34 61 91 127 169III: 12 27 30 36 42IV: 15 3 6 ; 6 Clearly, the given series becomes a triangular pattern series if each term in IV: is 6. Again, in II: 34 must be replaced by (61 - 24) i.e., 37 and 22 by (37 - 18) i.e., 19. Thus, in the given series, 27 is wrong and must be replaced by (5 + 19) i.e., 24.
209.
34, 30, 26, 22, 18, 14, 10, ... choose which pair of numbers comes next?
(A) 8, 6
(B) 6, 4
(C) 14, 18
(D) 6, 2
Solution:
This is a simple subtraction series, in which 4 is subtracted from each number to arrive at the next.
210.
In the following number series a wrong number is given. Find out the wrong number.
1, 3, 10, 21, 64, 129, 356, 777
(A) 129
(B) 21
(C) 10
(D) 356
Solution:
The given pattern is, 2nd term → 1*2+1 = 3 3rd term → 3*3+1 = 10 4th term → 10*2+1 = 21 5th term → 21*3+1 = 64 6th term → 64*2+1 = 129 7th term → 129*3+1= 388 So, 7th term 356 is wrong and must be replaced by 388.