\[\boxed{\mathbf{1043\ (1043).\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[b_{1} = 6\sqrt{3},\ \ S = 9 \cdot \left( \sqrt{3} + 1 \right),\]
\[\text{\ \ }|q| < 1\]
\[S = \frac{b_{1}}{1 - q} \Longrightarrow \ 1 - q = \frac{b_{1}}{S} \Longrightarrow \text{\ \ }\]
\[q = 1 - \frac{b_{1}}{S} = 1 - \frac{6\sqrt{3}}{9 \cdot \left( \sqrt{3} + 1 \right)} =\]
\[= \frac{9 \cdot \left( \sqrt{3} + 1 \right) - 6\sqrt{3}}{9 \cdot \left( \sqrt{3} + 1 \right)} =\]
\[= \frac{9\sqrt{3} + 9 - 6\sqrt{3}}{9 \cdot \left( \sqrt{3} + 1 \right)} =\]
\[= \frac{3\sqrt{3} + 9}{9 \cdot \left( \sqrt{3} + 1 \right)} = \frac{\sqrt{3} + 3}{3 \cdot \left( \sqrt{3} + 1 \right)} =\]
\[= \frac{\sqrt{3} \cdot \left( \sqrt{3} + 1 \right)}{3 \cdot \left( \sqrt{3} + 1 \right)} = \frac{\sqrt{3}}{3}\]
\[Ответ:q = \frac{\sqrt{3}}{3}.\]