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.

17 : 78 :: 15 : 68 :: 28 : ?

133

Pattern followed is :

17 : 78

17 × 5 = 85

85 - 7 = 78

&  15 : 68

15 × 5 = 75

75 - 7 = 68

Similarly ,

 28 : ?

28 × 5 = 140

140 - 7 = 133

133 , is correct answer .