# Sachin is younger than Rahul by 7 years. If their ages are in the respective ratio of 7 : 9, how old is Sachin?

A. 16 years B. 18 years C. 28 years D. 24.5 years Answer: Option D
$\begin{array}{l}\text{Let Rahul’s age be x years}\\ \text{Then,}\\ \text{Sachin’s age }=\left(x-7\right)\ \text{years}.\\ \begin{array}{l}\therefore\frac{x-7}{x}=\frac{7}{9}\\ \Rightarrow9x-63=7x\\ \Rightarrow2x=63\\ \Rightarrow x=31.5\\ \therefore\text{Sachin’s age}\\ =\left(x-7\right)\ \text{years}\\ =24.5\ \text{years}\end{array}\end{array}$