2 workers, each 8 per hour, for 40hrs a week, so one earns 8 * 40, or 320 bucks, is two workers, so 320 + 320 or 640 bucks
if 2000 is the 100%, how much is 640 in percentage off of it?
well [tex]\bf \begin{array}{ccllll}
amount&\%\\
\textendash\textendash\textendash\textendash\textendash\textendash&\textendash\textendash\textendash\textendash\textendash\textendash\\
2000&100\\ 640&x
\end{array}\implies \cfrac{2000}{640}=\cfrac{100}{x}[/tex]
solve for "x"