[tex]\bf \begin{array}{ccllll}
milk&water\\
\textendash\textendash\textendash\textendash\textendash\textendash&\textendash\textendash\textendash\textendash\textendash\textendash\\
\frac{1}{3}&\frac{1}{4}\\
1&x
\end{array}\implies \cfrac{\frac{1}{3}}{1}=\cfrac{\frac{1}{4}}{x}\implies \cfrac{\frac{1}{3}}{\frac{1}{1}}=\cfrac{\frac{1}{4}}{\frac{x}{1}}
\\\\\\
\cfrac{1}{3}\cdot \cfrac{1}{1}=\cfrac{1}{4}\cdot \cfrac{1}{x}\implies \cfrac{1}{3}=\cfrac{1}{4x}\implies 4x=3\implies x=\cfrac{3}{4}[/tex]
