Select the option that is related to the fifth number in the same way as the second number is related to the first number and the fourth number is related to the third number.

7 : 105 :: 9 : 153 :: 13 : ?

273

Pattern followed is :

X : X × ( X + 8 )

This pattern is followed by given series .

7 : 105                                       ::                    9 : 153

7 : 7 × ( 7 + 8 )                                         9 : 9 × ( 9 + 8 )

7 : 7 × 15                                                  9 : 9 × 17

7 : 105                                                     9 : 153

Similarly , 

13 : ?

13 : 13 × ( 13 + 8 ) 

13 : 13 × 21

13 : 273

273 is correct answer .