1.
If vectors 2i^j^+k^2\hat{i} - \hat{j} + \hat{k}, i^+2j^3k^\hat{i} + 2\hat{j} - 3\hat{k} and 3i^+aj^+5k^3\hat{i} + a\hat{j} + 5\hat{k} are coplanar, then the value of aa is