Respuesta :

[tex]\bf \begin{array}{|c|ll} \cline{1-1} \textit{a\% of b}\\ \cline{1-1} \\ \left( \cfrac{a}{100} \right)\cdot b \\\\ \cline{1-1} \end{array}~\hspace{5em}\stackrel{\textit{3\% of 50}}{\left( \cfrac{3}{100} \right)50}\implies 1.5~~gallons[/tex]