Seven years ago, the ages (in years) of A and B were in the ratio 4 : 5 and 7 years after, their ages will be in the ratio 5 : 6. What will be the ratio of their ages 5 years from now?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 34 : 41
Let age of A = a
and age of B = b
Before 7 years:
= (a - 7)/(b - 7) = (4/5)
⇒ 5a - 35 = 4b - 28
⇒ 5a - 4b = 7 ----------------- (1)
After 7 years:
(a + 7)/(b + 7) = 5/6
⇒ 6a + 42 = 5b + 35
⇒ 6a - 5b = -7 ------------------ (2)
On solving both the equations,
⇒ a = 63 and b = 77
Then again,
(a + 5)/(b + 5) = 68/82 = 34/41