Question:
Mark $(\sqrt{)}$ against the correct answer in each of the following:
If $\overrightarrow{\mathrm{a}}=(2 \hat{\mathrm{i}}+4 \hat{\mathrm{j}}-\hat{\mathrm{k}})$ and $\overrightarrow{\mathrm{b}}=(3 \hat{\mathrm{i}}-2 \hat{\mathrm{j}}+\lambda \hat{\mathrm{k}})$ be such that $\vec{a} \perp \vec{b}$ then $\boldsymbol{\lambda}=$ ?
A. 2
B. $-2$
C. 3
D. $-3$
Solution:
