well, we know they sell a total of about 1100 books monthly, and that nonfiction is 24% of that, what's 24% of 1100?
[tex]\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{24\% of 1100}}{\left( \cfrac{24}{100} \right)1100}\implies 264[/tex]
