# Aptitude - Odd Man Out and Series

### Exercise :: Odd Man Out and Series - Find Wrong No.

Find out the wrong number in the series.
1.

7, 8, 18, 57, 228, 1165, 6996

 A. 8 B. 18 C. 57 D. 228 E. 1165

Explanation:

Let the given numbers be A, B, C, D, E, F, G.

Then, A, A x 1 + 1, B x 2 + 2, C x 3 + 3, D x 4 + 4, E x 5 + 5, F x 6 + 6 are the required numbers.

Clearly, 228 is wrong.

2.

1, 1, 2, 6, 24, 96, 720

 A. 720 B. 96 C. 24 D. 6 E. 2

Explanation:

Go on multiplying with 1, 2, 3, 4, 5, 6 to get next number.

So, 96 is wrong.

3.

196, 169, 144, 121, 100, 80, 64

 A. 169 B. 144 C. 121 D. 100 E. 80

Explanation:

Numbers must be (14)2, (13)2, (12)2, (11)2, (10)2, (9)2, (8)2.

So, 80 is wrong.

4.

445, 221, 109, 46, 25, 11, 4

 A. 221 B. 109 C. 46 D. 25 E. 11

Explanation:

Go on subtracting 3 and dividing the result by 2 to obtain the next number.

Clearly, 46 is wrong.

5.

190, 166, 145, 128, 112, 100, 91

 A. 100 B. 166 C. 145 D. 128 E. 112

Explanation:

Go on subtracting 24, 21, 18, 15, 12, 9 from the numbers to get the next number.

```190 - 24 = 166
166 - 21 = 145
145 - 18 = 127 [Here, 128 is placed instead of 127]
127 - 15 = 112
112 - 12 = 100 ... and so on.
```

Therefore, 128 is wrong.