Calculate the efficiency of packing in case of a metal crystal for: body-centred cubic

Calculate the efficiency of packing in case of a metal crystal for: face-centred cubic (with the assumptions that atoms are touching each other).

Calculate the efficiency of packing in case of a metal crystal for face centred cubic lattice.

Calculate the efficiency of packing in case of a metal crystal for: Simple cubic

Calculate tbe packing efficiency of a metal crystal for a simple cubic lattice.

The packing fraction for a body centred cube is

In which part most efficiency packing is present?