Answer :
[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{0.8\% of 5700}}{\left( \cfrac{0.8}{100} \right)5700}\implies 45.6[/tex]