Concept:Use the ratio 5:3 to express their ages as 5x and 3x, then use the given future age to find x.Explanation:Let Swati's present age be 5x and Somni's present age be 3x.After 6 years, Swati's age will be 5x+6.Given that she will be 36 years old then, we get:5x+6=36⇒5x=30⇒x=6Somni's present age is:3x=3×6=18 yearsAnswer:Somni is now 18 years old, so the correct option is A. 18 years.