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.

26 -168

THE LOGIC;

1) 18 - 81: The relationship here is that 18 squared \( {18}^ {2} \) equals 324, which is the reverse of 81.

2) 34 - 289: The relationship here is that 34 squared \( {34}^ {2} \) equals 1,156, which is the reverse of 289.

3) 26 - 168: The relationship here is that 26 squared \( {26}^ {2} \) equals 676, which is the reverse of 168.

4) 16 - 64: The relationship here is that 16 squared \( {16}^ {2} \) equals 256, which is the reverse of 64.

Thus, all pairs follow the pattern of the square of the first number being the reverse of the second number, except for the pair 26 - 168.