Verbal Reasoning - Series Completion

Directions to Solve

In this type of questions, one term in the number series is wrong. Find out the wrong term.


21.
25, 36, 49, 81, 121, 169, 225
36
49
169
225
Answer: Option
Explanation:

The correct sequence is 52, 72, 92, 112, 132, 152. So, 36 is wrong.


22.
1, 3, 10, 21, 64, 129, 356, 777
21
129
10
356
Answer: Option
Explanation:

The correct pattern is x 2 + 1, x 3 + 1, x 2 + 1, x 3 + 1,.....

So, 356 is wrong and must be replaced by (129 x 3 + 1) i.e. 388.


23.
5, 10, 40, 80, 320, 550, 2560
80
320
550
2560
Answer: Option
Explanation:

The correct pattern is x 2, x 4, x 2, x 4, .....

So, 550 is wrong and must be replaced by (320 x 2) i.e. 640.


24.
2, 3, 4, 4, 6, 8, 9, 12, 16
3
6
9
12
Answer: Option
Explanation:

The given sequence is a combination of three series:

I. 1st, 4th, 7th terms i.e. 2, 4, 9,.....

II. 2nd, 5th, 8th terms i.e. 3, 6, 12,.....

III. 3rd, 6th, 9th terms i.e. 4, 8, 16,.....

In each one of I, II and III, each term is twice the preceding term. So, 9 is wrong and must be replaced by (4 x 2) i.e. 8.


25.
11, 5, 20, 12, 40, 26, 74, 54
5
20
40
26
Answer: Option
Explanation:

The given sequence is a combination of two series :

I. 11, 20, 40, 74 and II. 5, 12, 26, 54

The correct pattern in I is + 9, + 18, + 36,.....

So, 40 is wrong and must be replaced by (20 + 18) i.e. 38.