Correct Answer - Option 3 : 15
Let the age of Amit be 'x' years.
Age of Arjun = x + 6 years
Ratio of the ages of Amit and Arjun is 5 : 7
Therefore,
x/x + 6 = 5/7
⇒ 7x = 5(x + 6)
⇒ 7x = 5x + 30
⇒ 2x = 30
⇒ x = 15
Amit's age is 15 years.
Hence, 15 is the correct answer.