Correct Answer - Option 4 : 6 : 5
Ratio between the present ages of A and B = 5 : 4
Let;
Age of A = 5x
Age of B = 4x
According to question;
Age of A = Age of B + 3
5x = 4x + 3
5x - 4x = 3
x = 3
So, Age of A = 5 × 3 = 15 years
Age of B = 4 × 3 = 12 years
The age of A after 3 years = 15 + 3 = 18 years
The age of B after 3 years = 12 + 3 = 15 years
Ratio of the ages of A and B after 3 years = 18 : 15
= 6 : 5
Hence, "6 : 5" is the correct answer.