The same operation(s) are followed in all the given number pairs except one. Find that odd number pair.
(NOTE : Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13 – Operations on 13 such as adding /deleting /multiplying etc., to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.) bxs

Logic: multiply by 3 and then add +3

Option(A): 12 : 39= 12×3=36, 36+3=39(logically follow)

Option(B): 15 : 48= 15×3=45, 45+3=48(logically follow)

​Option(C): 11 : 35= 11×3=33, 33+3=36(logically not follow)

Option(D): 13 : 42= 13×3=39, 39+3=42(logically follow)

Options A, B & D follow the same pattern except C

Thus, option C is the correct answer.