The density of a pure substance A whose atoms pack in cubic close pack arrangement is 1 gm/cc. If B atoms can occupy tetrahedral void without distortions and they occupy all the tetrahedral voids, then what is the density of resulting solid m gm/cc?

[Given : ${\mathrm{M}}_{\mathrm{A}} = 30$ amu, ${\mathrm{M}}_{\mathrm{B}}$ = 50 amu]