The present age of Mr. Sanyal is three times the age of his son. Six years hence , the ratio of their ages will be 5 : 2. What is the present age of Mr. Sanyal ?

Answer: Option C

Let the son's age be $$x$$ years ,
Then Mr. Sanyal's age = 3$$x$$ years
$$\begin{array}{rl}& \therefore \frac{3x+6}{x+6}=\frac{5}{2}\\ & \Rightarrow 2\left(3x+6\right)=5\left(x+6\right)\\ & \Rightarrow 6x+12=5x+30\\ & \Rightarrow x=18\end{array}$$
∴ Present age of Mr. Sanyal = 3x years
= (3 × 18) years
= 54 years