What are the coordination numbers of $bcc$,$scc$,and $fcc$ respectively?

In a solid $AB$,$A$ atoms are in $ccp$ arrangement and $B$ atoms occupy all the octahedral sites. If two atoms from the opposite faces are removed,then the resultant stoichiometry of the compound is $A_{x} B_{y}$. The value of $x$ is ..... [nearest integer]

Explain the calculation of the number of atoms in a body-centered cubic $(bcc)$ unit cell.

The crystal structure of $AB$ is of $NaCl$ type. If the radius of the $A^+$ ion is $x \ pm$ and the radius of the $B^-$ ion is $y \ pm$, then the edge length of the unit cell will be ..........

If the edge length of a cubic unit cell is $a$,then the octahedral void is located at a distance of ....... from the corner of the cube.

The number of atoms in body-centred and face-centred cubic unit cells are,respectively: