At present, the ratio between the ages of Karim and Rahim is 4 : 3. After 6 years, Karim's age will be 26 years. What is the age of Rahim at present?

Question: At present, the ratio between the ages of Karim and Rahim is 4 : 3. After 6 years, Karim's age will be 26 years. What is the age of Rahim at present?

Solution:
Let the present ages of Karim and Rahim are 4k and 3k years respectively
{since their ages are in the ratio 4 : 3}.

After 6 years, Karim’s age will is 4k + 6 = 26
⇒ 4k = 26 - 6
⇒ 4k = 20
⇒ k = 20/4
∴ k = 5 years

Therefore, Rahim’s present age = 3k = 3 × 5 = 15 years.