SSC CGL Model Paper 16

Concept:In number-pair questions, check whether the second number is the square of the first number. The pair that does not follow this rule is the odd pair.Explanation:Check each option using the square relation. Option A: $11^2 = 121$, so $11 - 121$ is correct. Option B: $13^2 = 169$, so $13 - 169$ is correct. Option C: $19^2 = 361$, but the given pair is $19 - 391$, so it is incorrect. Option D: $21^2 = 441$, so $21 - 441$ is correct. Only option C does not follow the square rule.Answer:Option C: $19 - 391$