To calculate the percentage that some quantity is of another one, we calculate the ration from the part we want to calculate by the one which is the 100% and multiplicate it by 100. The result is the percentage.
From this, we can calculate as follows:
[tex]\begin{gathered} P_{\text{ \%}}=\frac{V_{to\text{ calculate}}}{V_{\text{ which is 100\%}}}\times100\text{ \%} \\ P=\frac{12}{15}\times100=0.8\times100=80\text{ \%} \end{gathered}[/tex]From the calculation presented, we are able to conclude that 12 gallons represent 80% of 15 gallons.
