What is to be added to 15% of 180 so that the sum is equal to 20% of 360?

Answer: Option A

$$\begin{array}{rl}& \text{Let be the number is }x\\ & 180\times \frac{15}{100}+x=\frac{360\times 20}{100}\\ & 27+x=72\\ & x=72-27\\ & x=45\end{array}$$