If a student has a hydrochloric acid solution that is 12.5% Hydrochloric acid by volume and the total volume of solution is 200 mL. The volume of hydrochloric acid taken is-

Volume by volume percentage is expressed as (Volume of solute per Volume of solution) multiplied by 100 .
$\text{ Volume }\%\text{ of }\mathrm{HCl}=\frac{\text{ Volume of }\mathrm{HCl}}{\text{ Total Volume of solution }}\times 100$
$12.5=\frac{\text{ Volume of }\mathrm{HCl}}{200 \mathrm{mL}}\times 100$
$\therefore \text{ Volume of }\mathrm{ICl}=\frac{12.5\times 200 \mathrm{mL}}{100}=25.0 \mathrm{mL}$
Hence, the volume of hydrochloric acid taken is $25.0 \mathrm{mL}$.