If $\left[\overline{a} \overline{b} \overline{c}\right]=3$ then the volume (in cubic units) of the parallepiped with $2\overline{\mathrm{a}}+\overline{\mathrm{b}}, 2\overline{\mathrm{b}}+\overline{\mathrm{c}}, 2\overline{\mathrm{c}}+\overline{\mathrm{a}}$ as coterminous edges is