[tex]\text{Given that,}\\\\\text{Mass}~ m = 68 ~\text{g} = 68 \times 10^{-3}~ \text{kg}\\\\\text{Volume}~ V = 80 ~ \text{cm}^3 = 80 \times 10^{-6}~ \text{m}^3 = 8\times 10^{-5}~ \text{m}^3\\\\\\\text{Density} ~\rho = \dfrac mV = \dfrac{68\times 10^{-3}}{8 \times 10^{-5}} = 8.5 \times 10^2 = 850 ~ \text{kg}~\text{m}^{-3}[/tex]