\[\frac{16}{500} \cdot 100 = \frac{16 \cdot 100}{500}\% =\]
\[= \frac{16}{5}\% = 3\frac{1}{5}\% = 3,2\% -\]
\[содержание\ соли\ в\ растворе.\]
\[Ответ:3,2\%.\]