The second number in the given number pairs is obtained by performing certain mathematical operation(s) on the first number. The same operation(s) are followed in all the number pairs except one. Find that odd number pair.

11 : 49

The logic followed here is;

--> Option 01 = 9 : 125

So, 125 is cube of 5

--> Option 02 = 11 : 49

So, 49 is not cube of any number, its a square of 07

--> Option 03 = 13 : 343

So, 343 is cube of 07

--> Option 04 = 7 : 64

So, 64 is cube of 04

Thus, 11 : 49 is odd one