[tex]\bf \begin{array}{ccll}
\stackrel{lbs}{spice}&\stackrel{cups}{cinnamon}\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
\frac{3}{4}&\frac{5}{6}\\\\
1&c
\end{array}\implies \cfrac{\frac{3}{4}}{1}=\cfrac{\frac{5}{6}}{c}\implies \cfrac{\frac{3}{4}}{\frac{1}{1}}=\cfrac{\frac{5}{6}}{\frac{c}{1}}\implies
\cfrac{3}{4}\cdot \cfrac{1}{1}=\cfrac{5}{6}\cdot \cfrac{1}{c}
\\\\\\
[/tex]
[tex]\bf \cfrac{3}{4}=\cfrac{5}{6c}\implies 18c=20\implies c=\cfrac{20}{18}\implies c=\cfrac{10}{9}\implies c=1\frac{1}{9}
[/tex]
