If x : y = 3 : 4, then the value of (4x - y) : (2x + 3y) is = ?

Answer: Option A

$$\begin{array}{rl}& x:y=3:4\\ & \therefore \frac{x}{y}=\frac{3}{4}\\ & \Rightarrow \frac{4x-y}{2x+3y}\\ & \Rightarrow \frac{y\left(4\frac{x}{y}-1\right)}{y\left(2\frac{x}{y}+3\right)}\\ & \Rightarrow \frac{4\times \frac{3}{4}-1}{2\times \frac{3}{4}+3}\\ & \Rightarrow \frac{\left(3-1\right)\times 2}{3+6}\\ & \Rightarrow \frac{4}{9}\\ & \Rightarrow 4:9\end{array}$$