\[\frac{15^{(n + 1)} \cdot 2^{n}}{6^{n} \cdot 5^{n}} = \frac{15^{n} \cdot 15 \cdot 2^{n}}{30^{n}} =\]
\[= \frac{30^{n} \cdot 15}{30^{n}} = 15\]
\[Ответ:\ 15.\ \]