The ages of Samina and Suhana are in the ratio of 7 : 3 respectively. After 6 years, the ratio of their ages will be 5 : 3. What is the difference in their ages?

A. 6 years

B. 8 years

C. 10 years

D. 12 years

E. None of these

Answer: Option B

Solution(By Examveda Team)

Let Samina's age be 7x years.
Then, Suhana's age = 3x years
$$\eqalign{ & \therefore \frac{{7x + 6}}{{3x + 6}} = \frac{5}{3} \cr & \Rightarrow 3\left( {7x + 6} \right) = 5\left( {3x + 6} \right) \cr & \Rightarrow 21x + 18 = 15x + 30 \cr & \Rightarrow 6x + 12 \cr & \Rightarrow x = 2 \cr} $$
Difference in their ages = (7x - 3x) years
= 4x years
= (4 × 2) years
= 8 years