Home > Practice > Verbal Reasoning > Series Completion > Miscellaneous
181. One term in the number series is wrong. Find out the wrong term.
6, 15, 35, 77, 165, 221

Discuss
Solution:
The terms of the series are products of two consecutive prime numbers i.e. (2 x 3),
(3 x 5), (5 x 7), (7 x 11),.....
So, 165 is wrong and must be replaced by (11 x 13) i.e. 143.
182. One term in the number series is wrong. Find out the wrong term.
8, 13, 21, 32, 47, 63, 83

Discuss
Solution:
The correct pattern is + 5, + 8, + 11, + 14,.....
So, 47 is wrong and must be replaced by (32 + 14) i.e. 46.
183. One term in the number series is wrong. Find out the wrong term.
1, 2, 4, 8, 16, 32, 64, 96

Discuss
Solution:
Each term of the series is obtained by multiplying the preceding term by 2.
So, 96 is wrong and must be replaced by (64 x 2) i.e. 128.
184. One term in the number series is wrong. Find out the wrong term.
3, 4, 10, 32, 136, 685, 4116

Discuss
Solution:
The correct pattern is x 1 + 1, x 2 + 2, x 3 + 3, x 4 + 4,.....
So, 32 is wrong and must be replaced by (10 x 3 + 3) i.e. 33.
185. One term in the number series is wrong. Find out the wrong term.
105, 85, 60, 30, 0, - 45, - 90

Discuss
Solution:
The correct pattern is - 20, - 25, - 30,.....
So, 0 is wrong and must be replaced by (30 - 35) i.e. - 5.
186. One term in the number series is wrong. Find out the wrong term.
2, 5, 10, 17, 26, 37, 50, 64

Discuss
Solution:
The terms of the series are (12 + 1), (22 + 1), (32 + 1), (42 + 1), (52 + 1), (62 + 1),

(72+1),.....
So, 64 is wrong and must be replaced by (82 + 1) i.e. 65.

187. One term in the number series is wrong. Find out the wrong term.
125, 126, 124, 127, 123, 129

Discuss
Solution:
The correct pattern is + 1, - 2, + 3, - 4, + 5.
So, 129 is wrong and must be replaced by (123 + 5) i.e. 128.
188. One term in the number series is wrong. Find out the wrong term.
2, 5, 10, 50, 500, 5000

Discuss
Solution:
Each term of the series is the product of the preceding two terms.
So, 5000 is wrong and must be replaced by (50 x 500) i.e. 25000.
189. One term in the number series is wrong. Find out the wrong term.
1, 3, 12, 25, 48

Discuss
Solution:
The terms of the series are (l2 - 02), (22 - l2), (42 - 22), (62 - 32) and (82 - 42).
So, 25 is wrong and must be replaced by (62 - 32) i.e. 27.
190. One term in the number series is wrong. Find out the wrong term.
15, 16, 22, 29, 45, 70

Discuss
Solution:
The correct pattern is + 1, + 4, + 9, + 16, + 25 i.e. + 12, + 22, + 32, + 42, + 52.
So, 22 is wrong and must be replaced by (16 + 4) i.e. 20.