Solve this : 85% of 485.5 = 50% of ?

Answer: Option C

Lets 85% of 485.5 = 50% of x
Then,
$$\begin{array}{rl}& \Rightarrow \left(\frac{85}{100}\times 485.5\right)=\frac{50x}{100}\\ & \Rightarrow \frac{x}{2}=412.675\\ & \Rightarrow x=825.35\end{array}$$