Select the number-pair in which the two numbers are related in the same way as are the two numbers of the following number-pair.
25 : 600

25:600 

25²-25 = 625-25 = 600 

similarly following the same pattern we will get

18:306

18²-18 = 324-18 = 306

Hence option 4 is the correct answer.

By: Himani Bihagra