If $\begin{vmatrix}a&b&c\\m&n&p\\x&y&z\end{vmatrix}=k$, then $\begin{vmatrix}6a&2b&2c\\3m&n&p\\3x&y&z\end{vmatrix}=$

$\frac{k}{6}$ $2k$ $3k$ $6k$

$6k$

Taking 3 common from $C_1$ and 2 from $R_1$ $\begin{vmatrix}6a&2b&2c\\3m&n&p\\3x&y&z\end{vmatrix}=3×2\begin{vmatrix}a&b&c\\m&n&p\\x&y&z\end{vmatrix}=6k$