# Aptitude - Odd Man Out and Series - Discussion

### Discussion :: Odd Man Out and Series - Odd Man Out (Q.No.7)

Find the odd man out.

7.

1, 4, 9, 16, 20, 36, 49

 [A]. 1 [B]. 9 [C]. 20 [D]. 49

Explanation:

The pattern is 12, 22, 32, 42, 52, 62, 72. But, instead of 52, it is 20 which to be turned out.

 Sonutalwani said: (Jun 28, 2012) 1*1=1. 2*2=4. 3*3=9. 4*4=16. 6*6=36. 7*7=49. 20 is not a square of any number.

 Prashant Kamble said: (Aug 5, 2013) all numbers are perfect square except 20.

 Salman Baig said: (Dec 15, 2015) Another way to solve this: 1, 4, 9, 16, 20, 36, 49. O, E, O, E, E, E, O. There should be some odd no in series instead 20 which is even no.

 Saylee said: (Sep 7, 2016) All are square numbers expect 20.

 Ligesh Kp said: (Nov 2, 2016) As per my logic, 1 + 3 = 4 4 + 5 = 9 9 + 7 = 16 16 + 9 = 25 25 + 11 = 36 36 + 13 = 49 So 25 is missing here.

 Subhadeep Maji said: (Jan 29, 2018) 1^2, 2^2, 3^2, 4^2, 5^2, 6^2, 7^2. As per the question 20 is not a perfect square whereas C is the correct answer.