Let \(\vec{a} = \hat{i} + 4\hat{j} + 2\hat{k}, \; \vec{b} = 3\hat{i} - 2\hat{j} + 7\hat{k} \; and\; \vec{c} = 2\hat{i} - \hat{j} + 4\hat{k}\) find the vector \(\vec{d}\) which is perpendicular to both \(\vec{a}\; and\; \vec{b} \; and \; \vec{c}\;.\; \vec{d}\) = 15