how do i determine the density of a sphere in kg/ L if the mass is 675.1 mg and the radius is 48.3cm how do i determine the volume of a rectangular...

1. how do i determine the density of a sphere in kg/ L if the mass is 675.1 mg and the radius is 48.3cm
2. how do i determine the volume of a rectangular prism with a density of 5.43*103 mg/ml and a mass of 3.89*104g. The volume must be in liters
3. how do i calculate the mass (g) of a cylinder with a density of 2.20*10-2 kg/L, radius of 12.70 m and length of 53.94 m.

Thanks for your help