\[\boxed{\mathbf{3.44}}\]
Пояснение.
Решение.
\[\textbf{а)}\ 4\ :16 = 7\ :28\]
\[\frac{4}{16} = \frac{7}{28};\ \frac{16}{4} = \frac{28}{7};\ \frac{4}{7} = \frac{16}{28};\ \frac{7}{4} =\]
\[= \frac{28}{16}.\]
\[\textbf{б)}\ \frac{24}{0,4} = \frac{36}{0,6}\]
\[\frac{0,4}{24} = \frac{0,6}{36};\ \ \frac{0,6}{0,4} = \frac{36}{24};\ \ \frac{0,4}{0,6} = \frac{24}{36}\text{.\ \ \ }\]
\[\textbf{в)}\ \frac{p}{q} = \frac{l}{k}\]
\[\frac{q}{p} = \frac{k}{l};\ \ \frac{q}{k} = \frac{p}{l};\ \ \frac{k}{q} = \frac{l}{p}.\]