Question

Four number-pairs have been given, out of which three are alike in some manner and one is different. Select the one that is different.

• A. 11 ∶ 123
• B. 17 ∶ 291
• C. 15 ∶ 227
• D. 13 ∶ 169

Answer 1

Answer:

D. 13 ∶ 169

(1) 11 : 123 → 11^2 + 2 = 121 + 2 = 123 (2) 17 : 291 → 17^2 + 2 = 289 + 2 = 291 (3) 15 : 227 → 15^2 + 2 = 225 + 2 = 227 (4) 13 : 169 → 13^2 + 2 = 169 + 2 = 171 ≠ 169