The ages of Sulekha and Arunima are in the ratio 9 : 8 respectively. After 5 years, the ratio of their ages will be 10 : 9. What is the difference in their ages ?

A. 4 years

B. 5 years

C. 6 years

D. 7 years

E. None of these

Answer: Option B

Solution(By Examveda Team)

Let Sulekha age be 9 year,
Then Arunima's age = 8x years
$$\eqalign{ & \frac{{9x + 5}}{{8x + 5}} = \frac{{10}}{9} \cr & \Rightarrow 9\left( {9x + 5} \right) = 10\left( {8x + 5} \right) \cr & \Rightarrow 81x + 45 = 80x + 50 \cr & \Rightarrow x = 5 \cr} $$
Difference in their ages
= (9x - 8x) years
= x years
= 5 years