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 (-) 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)

2 - 18

The logic followed here is :

(Ist term × 10) = IInd term

6 - 60 = 6 × 10 = 60

2 - 18 = 2 × 9 = 18 ODD

4 - 40 = 4× 10 = 40

8 - 80 = 8 × 10 = 80