\[\boxed{\text{5.394.}}\]
\[\textbf{а)}\ \frac{7}{15} > \frac{1}{60}\ \]
\[\frac{7}{15} = \frac{28}{60} > \frac{1}{60}\text{.\ }\]
\[\textbf{б)}\ \frac{6}{15} < \frac{15}{25}\]
\[\frac{6}{15} < \frac{15}{25} = \frac{3}{5} = \frac{9}{15}\text{.\ \ }\]