Respuesta :

[tex]\bf \begin{array}{ccllll} photos&minutes\\ \textendash\textendash\textendash\textendash\textendash\textendash&\textendash\textendash\textendash\textendash\textendash\textendash\\ 28&8\\ 21&x \end{array}\implies \cfrac{28}{21}=\cfrac{8}{x}[/tex]

solve for "x"