The ratio of the ages of A and B is 3 : 4. Four years ago, the ratio of their ages was 5 : 7. What will be the ratio of the ages of A and B four years from now?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 7 : 9.
Let the current age of A = 3x and B = 4x
(3x - 4)/(4x - 4) = 5/7
⇒ 21x - 28 = 20x - 20
⇒ x = 8
Current Ages: A = 3x = 24 years and B = 4x = 32 years
New ratio = (24 + 4) : (32 + 4) = 28 : 36 = 7 : 9