So we wan't to find the density of a body with a mass m= 700 kg and volume V=649 m^3. The definition of density is density=mass/volume or D=m/V. So after inserting the numbers we have: D=700kg/649m^3 and that is D= 1.078582 kg/m^3 and rounded to 3 significant figures: D=1.08 kg/m^3