\[\frac{14}{15}\ :y = \frac{21}{25}\]
\[y = \frac{14}{15}\ :\frac{21}{25}\]
\[y = \frac{14}{15} \cdot \frac{25}{21} = \frac{2 \cdot 5}{3 \cdot 3} = \frac{10}{9}\]
\[y = 1\frac{1}{9}.\]