so, the count went down from 850 to 500, or 350 units.
if we take the 850 to be the 100%, what is 350 in percentage off of it?
[tex]\bf \begin{array}{ccllll}
amount&\%\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
850&100\\
350&x
\end{array} \implies \cfrac{850}{350}=\cfrac{100}{x}[/tex]
solve for "x".
