The ratio of the age of a son after 15 years and the present age of his father is 2 : 3. 5 years ago, the age of the father was 4 times the age of the son. The present ages (in years) of the father and the son, respectively, are:

Correct option is A

Given:

Son’s age after 15 years : Father’s present age = 2 : 3

5 years ago, father’s age = 4 × (son’s age).

Solution:
Let present ages be: son = s, father = f.

Ratio →$$\dfrac{s+15}{f}=\dfrac{2}{3}$$​​

f =$$\dfrac{3}{2}(s+15)=1.5s+22.5$$​​
Now, 

f - 5= 4(s - 5)
1.5s + 22.5 - 5 = 4(s - 5)

1.5s + 17.5 = 4s - 20
37.5=2.5s 

s = 15.
Then f$$=\dfrac{3}{2}(15+15)=\dfrac{3}{2}\times30=45$$​​

Father = 45 years, Son = 15 years.