[tex]\begin{array}{ccll} batches&cups\\ \cline{1-2} 1&\frac{1}{2}\\[1em] x&2 \end{array}\implies \cfrac{1}{x}=\cfrac{~~\frac{1}{2} ~~}{2}\implies \cfrac{1}{x}=\cfrac{~~\frac{1}{2} ~~}{\frac{2}{1}}\implies \cfrac{1}{x}=\cfrac{1}{2}\cdot \cfrac{1}{2} \\\\\\ \cfrac{1}{x}=\cfrac{1}{4}\implies 4=x[/tex]
