​The ratio of the present ages of Shinjan and Aamya is 3 : 4. After 10 years this ratio will become 5 : 6. The present age (in years) of Aamya is:

Correct option is B

​Given:
Ratio of ages (Shinjan : Aamya) = 3:4,

after 10 years ratio = 5:6.

Solution:
Let present ages be 3x and 4x. After 10 years:

​$$\frac{3x + 10}{4x + 10} = \frac{5}{6}$$​​

6(3x + 10) = 5(4x + 10)

18x + 60 = 20x + 50

​$$2x = 10 \\ \ \\ x = 5$$​​

Thus, Present age of Aamya = 4x = 20 years