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
84.
What will come at the place of question mark ? 2, 3, 6, 15, ?, 123
(A) 47
(B) 42
(C) 45
(D) 50
Solution:
First term → 2 Second term → (2 *3 -3) = 3 Third term → (3 *3 -3) = 6 Fourth term → (6 *3 - 3) = 15 Fifth term → (15 *3 - 3) = 42 Sixth term → (42 *3 - 3) = 123
85.
8, 22, 8, 28, 8, ... What number should come next?
(A) 9
(B) 29
(C) 32
(D) 34
Solution:
This is a simple addition series with a random number, 8, interpolated as every other number. In the series, 6 is added to each number except 8, to arrive at the next number.
86.
Find the missing number: 3, 7, 15 ,?, 63 ,127
(A) 30
(B) 31
(C) 47
(D) 52
Solution:
Each number in the series is one more than twice the preceding number.So, the missing term = (15 x 2) + 1 = 31
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
88.
Find out the wrong term: 1236, 2346, 3456, 4566, 5686
(A) 1236
(B) 3456
(C) 4566
(D) 5686
Solution:
The correct pattern in the series is + 1110. So, 5686 is wrong and must be replaced by (4566 + 1110) i.e., 5676.
89.
Find the missing term: 8, 28, 116, 584 , ?
(A) 1752
(B) 3502
(C) 3504
(D) 3508
Solution:
The pattern is x3+4, x4+4, x5+4,...............So, missing term=584x6+4=3508
90.
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.