Practice MCQ Questions and Answer on Number Series Completion
21.
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.
75, 65, 85, 55, 45, 85, 35, ... choose which pair of numbers comes next?
(A) 25, 15
(B) 25, 85
(C) 35, 25
(D) 85, 35
Solution:
This is a simple subtraction series in which a random number, 85, is interpolated as every third number. In the subtraction series, 10 is subtracted from each number to arrive at the next.
24.
10, 20, 25, 35, 40, 50, 55, ... choose which pair of numbers comes next?
(A) 70, 65
(B) 60, 70
(C) 60, 75
(D) 60, 65
Solution:
Answer & Solution Answer: Option E Solution: This is an alternating addition series, in which 10 is added, then 5, then 10, and so on.
25.
(1/9), (1/3), 1, ____ , 9. What number should fill the blank?
(A) (2/3)
(B) 3
(C) 6
(D) 27
Solution:
This is a multiplication series; each number is 3 times the previous number.
26.
Find the missing term: 5760, 960, ?, 48, 16, 8
(A) 120
(B) 160
(C) 192
(D) 240
Solution:
The pattern is ÷ 6, ÷ 5, ÷ 4, ÷ 3, ÷ 2 So, missing term = 960 ÷ 5= 192
27.
Find the missing term: 10, 100, 200, 310. ?
(A) 400
(B) 410
(C) 420
(D) 430
Solution:
The pattern is + 90, + 100, + 110...... So, the missing term = 310 + 120 = 430
28.
Find the missing term: 6, 12, 21, ?, 48
(A) 33
(B) 38
(C) 40
(D) 45
Solution:
The pattern is +6, +9, +12, +15...............So, missing term=21+12=33
29.
17, 14, 14, 11, 11, 8, 8, ... choose which pair of numbers comes next?
(A) 8, 5
(B) 5, 2
(C) 8, 2
(D) 5, 5
Solution:
This is a simple addition series with repetition. It subtracted 3 to each number to arrive at the next, which is repeated before 3 is subtracted again.
30.
32, 29, 26, 23, 20, 17, 14, ... choose which pair of numbers comes next?
(A) 11, 8
(B) 12, 8
(C) 11, 7
(D) 32, 29
Solution:
In this simple subtraction series, the numbers decrease by 3.