Correct Answer: Option B
Let the ages of father and son 10 years ago be 3x and x years respectively.
Then, (3x + 10) + 10 = 2[(x + 10) + 10]
=> 3x + 20 = 2x + 40
=> x = 20.
Therefore, Required ratio = (3x + 10) : (x + 10)
= 70 : 30 = 7 : 3.
Download our app for free and access thousands of MCQ questions with detailed solutions