Question

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 $\vec{b}$ .$\vec{c}$=12, then |$\vec{c} \times(\vec{a} \times \vec{b})$| is equal to:

• A. 9
• B. 15
• C. 6
• D. 12

Answer 1

Answer: (D)

12

Answer 2

The correct option is (D) : 12