Correct Answer - Option 1 : 4 years
Given:
Rohit’s age = 16 years
Aadi’s age = 20 years
Concept Used:
Ratio concept used.
Calculation:
Let ‘x’ years ago the ratio of their ages was 3 ∶ 4.
According To the Question,
{(16 – x)/(20 – x)} = 3/4
⇒ 4(16 – x) = 3(20 – x)
⇒ 64 – 4x = 60 – 3x
⇒ 4x – 3x = 64 – 60
⇒ x = 4
∴ 4 years ago ratio of their ages was 3 ∶ 4.
Always try to approach these kinds of problems by taking a look at the options.