Find the odd one out among the following numbers.
- 181
- 169
- 121
- 144
Show answer and solution
Correct answer: A. 181
1. Check each for being a perfect square: 169 = 13², 121 = 11², 144 = 12².
2. For 181, note 13² = 169 and 14² = 196, so 181 is not a perfect square.
3. Therefore 181 is the odd one out.
_Source: RRB Group D (RRC) PYQ, held 27-10-2013, Q.87._