Q. If $\vec{a}, \vec{b}, \vec{ c }$ are three non-zero vectors and $\hat{n}$ is a unit vector perpendicular to $\vec{ c }$ such that $\vec{ a }=\alpha \vec{ b }-\hat{ n },(\alpha \neq 0) $ and $ \vec{ b } \cdot \vec{ c }=12$, then $|\vec{ c } \times(\vec{ a } \times \vec{ b })|$ is equal to :
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