20 + 8 × 0.520 - ? = 12 Find the value in place of (?)

Answer: Option C

Let the missing number is x
$$\begin{array}{rl}& \text{Given,}\\ & \frac{20+8\times 0.5}{20-x}\text{ = 12}\\ & \Rightarrow \frac{20+4}{20-x}=12\\ & \Rightarrow \frac{24}{20-x}=12\\ & \Rightarrow 20-x=\frac{24}{12}=2\\ & \Rightarrow x=20-2\\ & =18\\ & \text{Hence, the number is 18}\end{array}$$