Four number-pairs have been given, out of which three are alike in some manner and one is different. Select the number-pair that is different.
Answer & explanation
Correct answer: option 4
The logic is
Ist number : (Ist number + 1)2 - 1
7 : (7 + 1)2 - 1 = 7 : 63
4 : (5 + 1)2 - 1 = 5 : 35
13 : (13 + 1)2 - 1 = 13 : 195
19 : (19 - 1)2 = 19 : 324 (odd)