V=25x12x65=19500m^3 m=3,51kg m=pV p=m/V=3,51/19500=0.018*10^-2kg/m^3 =0,18*10^-3kg/m^3 2)V=25*12*656= 196800 m=3,51 p=m/V=3,51/196800=0.001*10^-2kg/m^3