The age of the older of two boys is thrice that of the younger. 9 years ago it was five times that of the younger. Find the present age of each.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 18 years, 54 years.
Let the age of the younger boy be X
According to the question,
The age of the older boy = 3X
9 years ago,
⇒ (3X - 9) = 5(X - 9)
⇒ 3X - 9 = 5X - 45
⇒ 2X = 36
⇒ X = 18 years
⇒ 3X = 18 × 3 = 54 years
Hence, the younger and older boys are 18 years, and 54 years respectively.