Here the requirement is to work out the volume.
Density is mass per unit volume.
Hence to get volume, divide mass by the density.
After you convert the pounds to grams, divide it by the density ie 2.130 gm/cm^3.
This gives you the volume in cm cube.
Now you need to convert it to kilometre cube.
1 cm = 10^-5 KM.
so 1 cm cubed = 10^-15 KM cubed.
Divide the volume in cm cube by this to get the answer in km cube.
