The ratio of a man’s age to his father’s age is 4 : 5, and the ratio of his age to his son’s age is 6 : 1. Four years ago these ratio were 11 : 14 : 1, respectively. The ratio of the age of the grandfather to that of grandson 12 years from now will be:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e 18 : 5
Let the age of man be 12x(LCM of 4,6) so the age of father be 15x & age of his son will be 2x.
The ratio of ages of man and son 4 years ago be ⇒ 11 = (12x - 4) / (2x - 4)
⇒ x = 4
Age of father = 15 × 4 = 60
Age of his grandson = 2 × 4 = 8
12 years hence the ratio will be = 72 / 20 = 18 / 5