Question
If vectors $\vec{a}=2 \hat{ i }+2 \hat{\jmath}+3 \hat{ k }, \vec{b}=-\hat{ i }+2 \hat{\jmath}+\hat{ k }$ and $\vec{c}=3 \hat{ i }+\hat{ j }$ are such that $\vec{b}+\lambda \vec{c}$ is perpendicular to $\vec{a}$, then find the value of $\lambda$.