Practice MCQ Questions and Answer on Number Series Completion
231.
201, 202, 204, 207, ... What number should come next?
(A) 205
(B) 208
(C) 210
(D) 211
Solution:
In this addition series, 1 is added to the first number; 2 is added to the second number; 3 is added to the third number; 4 is added to the fourth number; and go on.
232.
In a given series one term is wrong or missing term: 1, 5, 11, 19, 29, 55
(A) 55
(B) 41
(C) 29
(D) 19
Solution:
The correct sequence is + 4, + 6, + 8, + 10, ............So, next term after 29 = 29 + 12 = 41.The term after 41 will then be (41 + 14) i.e., 55.∴ 41 is missing.
233.
Find out the wrong term: 121, 143, 165, 186, 209
(A) 143
(B) 165
(C) 186
(D) 209
Solution:
Each term in the series is obtained by adding 22 to the preceding term.So, 186 is wrong and must be replaced by (165 + 22) i.e., 187.
234.
Find the missing term: 2, 5, 9, ?, 20, 27
(A) 14
(B) 16
(C) 18
(D) 24
Solution:
The pattern is +3, +4, +5, +6,........So, missing term=9+5=14
235.
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.
236.
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.
237.
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.
238.
3, 8, 13, 18, 23, 28, 33, ... choose which pair of numbers comes next?
(A) 39, 44
(B) 38, 44
(C) 38, 43
(D) 37, 42
Solution:
In this simple addition series, each number is 5 greater than the previous number.
239.
Find the missing term: 2, 2, 5, 13, 28, ?
(A) 49
(B) 50
(C) 51
(D) 52
Solution:
The pattern is + 0, + 3, + 8, + 15,.............i.e.,+ (12 - 1) , + (22 - 1), + (32 - 1), + (42 - 1),................ So, the missing term = 28 + (52 - 1) = 28 + 24 = 52
240.
What will come at the place of question mark ? 7, 11, 19, 35, 67, ?
(A) 99
(B) 131
(C) 137
(D) 124
Solution:
Logic: Last Term *2 - 3 = Next Term. First Term = 7 Second Term = 7 * 2 -3 = 11 Third Term = 11 * 2 - 3 = 19 Fourth Term = 19 * 2 - 3 = 35 Fifth Term = 35 * 2 - 3 = 67 Sixth Term = 67 * 2 -3 = 131 Alternative Solution : Last term + 2n = Next Term First Term = 7 Second Term = 7 + 22 = 11 Third Term = 11 + 23 = 19 Fourth Term = 19 + 24 = 35 Fifth Term = 35 + 25 = 67 Sixth Term = 67 + 26 = 131