2.0 g of a bromo hydrocarbon $(\mathrm{X})$ was subjected to Carius analysis, gave 3.36 g of AgBr . The percentage of carbon in the compound $(\mathrm{X})$ is $26.7 \%$. Total number of carbon atoms in the empirical formula for compound $(\mathrm{X})$ is $\_\_\_\_$ . (Given molar mass in $\mathrm{gmol}^{-1} \mathrm{H}: 1, \mathrm{C}: 12, \mathrm{Br}: 80, \mathrm{Ag}: 108$ )