SSC GD 2023 PYQ — Question 47

The correct answer is option 4 i.e. 15.

Let the given numbers, a, b, c, and d, be in the ratio.

So, 

a : b : c : d

= a/b = c/d

Let the fourth proportional of 3, 5, and 9 is x.

The fourth proportional = 3 : 5 : 9 : x

3/5 = 9/x

3x = 45

x = 45