Q.If the vectors $\vec{a} = \hat{i} - 2\hat{j} + 3\hat{k}$, $\vec{b} = -2\hat{i} + 3\hat{j} - 4\hat{k}$ and $\vec{c} = \hat{i} - 3\hat{j} + 5\hat{k}$ are coplanar, then the value of $\lambda$ in $\vec{a} + \lambda \vec{b} + \vec{c} = \vec{0}$ is