# Aptitude - Odd Man Out and Series - Discussion

Discussion Forum : Odd Man Out and Series - Find Wrong No. (Q.No. 5)
Directions to Solve
Find out the wrong number in the series.

5.
190, 166, 145, 128, 112, 100, 91
100
166
145
128
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.

Discussion:
11 comments Page 1 of 2.

Loyid said:   7 years ago
190 - 24(3 x 8) = 166,
166 - 21(3 x 7) = 145,
145 - 18(3 x 6) = 127 -----> Correct and 128 is wrong,
127 - 15(3 x 5) = 112,
112 - 12(3 x 4) = 100 -----> Multiples of 3 is subtracted from each number.

Hamsa said:   9 years ago
91-1 = 90.
100-1 = 99.
112-1 = 111.
128-1 = 127.
145-1 = 144.
166-1 = 165.

90, 99, 111, 144, 165 all are divisible by 3.

Except 127, So 128 is odd.

190-166= 24 =8x3
166-145= 21 =7x3
145-127= 18 =6x3 <=128 is wrong
127-112= 15 =5x3
112-100= 12 =4x3
100-91 = 9 =3x3

Ashish jat said:   7 years ago
When dividing numbers by 3 you will get remainder 1 but in 128 you will get remainder 2.

Hope it will help.

Joyto Roy said:   10 years ago
Out of all the numbers only 100 is a perfect square.

So, in the series 100 is only the odd one out.

Apoorv said:   7 years ago
100 could also be the answer as it's only prefect squared number in the series.

91+9=100
100+12=112
112+15=127 = 128 is wrong
127+18=145
145+21=166
166+24=190