Vector Algebra: JEE Main 2020 Mathematics question

Let $\overrightarrow a$, $\overrightarrow b$ and $\overrightarrow c$ be three vectors such that $\left| {\overrightarrow a } \right| = \sqrt 3$, $\left| {\overrightarrow b } \right| = 5,\overrightarrow b .\overrightarrow c = 10$ and the angle between $\overrightarrow b$ and $\overrightarrow c$ is ${\pi \over 3}$. If ${\overrightarrow a }$ is perpendicular to the vector $\overrightarrow b \times \overrightarrow c$ , then $\left| {\overrightarrow a \times \left( {\overrightarrow b \times \overrightarrow c } \right)} \right|$ is equal to _____.