Vector Algebra

If the vectors $2 \hat{\mathbf{i}}-\hat{\mathbf{j}}+3 \hat{\mathbf{k}}, \hat{\mathbf{i}}+4 \hat{\mathbf{j}}+\hat{\mathbf{k}}, 4 \hat{\mathbf{i}}+p \hat{\mathbf{j}}+\hat{\mathbf{k}}$ are coplanar, then $p=$