Rahim's present age is 9 times as Karim's age. After 9 years, Rahim's age would be 3 times as Karim's age. What is the present age of Karim?

Question: Rahim's present age is 9 times as Karim's age. After 9 years, Rahim's age would be 3 times as Karim's age. What is the present age of Karim?

Solution:
Let, Karim's present age be x years
and Rahim's present age is = 9x years

Now,
Karim's age after 9 years = (x + 9) years
Rahim's age after 9 years = (9x + 9) years

ATQ,
9x + 9 = 3(x + 9)
⇒ 9x + 9 = 3x + 27
⇒ 6x = 18
⇒ x = 3