[tex]\bf \begin{array}{ccllll}
liters&folks\\
\textendash\textendash\textendash\textendash\textendash\textendash&\textendash\textendash\textendash\textendash\textendash\textendash\\
1&5\\
x&7
\end{array}\implies \cfrac{1}{x}=\cfrac{5}{7}\implies 7\cdot 1=x\cdot 5
\\\\\\
\cfrac{7}{5}=x[/tex]
