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.

12 : 120 :: 20 : 360 :: 3 : ?

3

Pattern followed here is :

2nd number = (1st number ) × (1st number - 2 )

We have ,

12 : 120

2nd number = (12 ) × (12 - 2 )

= 12 × 10

= 120

&  20 : 360

2nd number = (20 ) × (20 - 2 )

= 20 × 18

= 360

Similarly ,

3 : ?

2nd number = (3 ) × (3 - 2 )

= 3 × 1

= 3

3 is correct answer .