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
The given sequence is a combination of two series:I. 45, 47, 49, 51, 53 andII. 54, ?, 56, 57Clearly, II. consists of consecutive natural numbers, starting from 54.so, missing term = 55.
115.
F2, __, D8, C16, B32 What number should fill the blank?
(A) A16
(B) G4
(C) E4
(D) E3
Solution:
The letters decrease by 1; the numbers are multiplied by 2.
116.
Find out the wrong term: 8, 13, 21, 32, 47, 63, 83
(A) 13
(B) 21
(C) 32
(D) 47
Solution:
The correct pattern is + 5, + 8, + 11, + 14, ............So, 47 is wrong and must be replaced by (32 + 14) i.e., 46
117.
Find the missing term: 1, 4, 10, 22, 46, ?
(A) 64
(B) 86
(C) 94
(D) 122
Solution:
The pattern is + 3, + 6, + 12, + 24,............. So, missing term = 46 + 48 = 94
118.
8, 12, 9, 13, 10, 14, 11, ... choose which pair of numbers comes next?
(A) 14, 11
(B) 15, 12
(C) 8, 15
(D) 15, 19
Solution:
This is an alternating addition and subtraction series, in which the addition of 4 is alternated with the subtraction of 3.
119.
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
120.
What will come at the place of question mark ? 3, 7, 23, 95, ?
(A) 62
(B) 128
(C) 479
(D) 575
Solution:
1st number = 3 2nd number = 3 x 2 +1 = 7 3rd number = 7 x 3 + 2 = 23 4th number = 23 x 4 + 3 = 95 5th number = 95 x 5 + 4 = 479