In the following question, four number pairs are given. In each pair the number on left side of (-) is related to the number of the right side of 9-) with some Logic/Rule/Relation. Three pairs are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives. (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/subtracting/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 )

9 - 16 

11 - 23 = (11 × 2) + 1 = 23

9 - 16 = (9 × 2) - 2 = 16 (odd)

25 - 51 = (25 × 2) + 1 = 51

13 - 27 = (13 × 2) + 1 = 27