Jharkhand PSC Prelim Exam 2006 Solved Paper

Let, age of Son = x
According to question,
Age of Father = 3x
After 5 years, Father age is 4times Son age = than Son age= x – 5
Then,Father age = 3x – 5
According to question,
(x – 5) × 4 = 3x – 5⇒ 15∴ Present age of Son= 15 years