How much water should be mixed with 12 ml of alcohol so as to obtain 12% of alcohol solution?

$$\begin{gathered} Volumepercent=\frac{Volumeofsolute\left(alcohol\right)}{Volumeofsolution} \\ 12\%=\frac{12}{Volumeofwater} \\ \frac{12}{100}=\frac{12}{Volumeofwater} \\ Volumeofwater=100ml \end{gathered}$$

100 ml of water should be mixed with 12 ml of alcohol so as to obtain 12% of alcohol solution.