If two vectors $2\widehat{i}+3\widehat{j}-\widehat{k}$ and $-4\widehat{i}-6\widehat{j}+\lambda \widehat{k}$ are parallel to each other then value of $\lambda$will be

$\overrightarrow{A}=2\widehat{i}+3\widehat{j}-\widehat{k}and\overrightarrow{B}=-4\widehat{i}-6\widehat{j}+\lambda \widehat{k}$       

$\overrightarrow{A}$ and $\overrightarrow{B}$are parallel to each other

$\frac{a_1}{b_1}=\frac{a_2}{b_2}=\frac{a_3}{b_3}i.e.,\frac{2}{-4}=\frac{3}{-6}=\frac{-1}{\lambda }\Rightarrow \lambda =2$