What is the total number of particles present in a base-centred unit cell?

The unit cell of a $NaCl$ lattice:

Which of the following contains rock salt structure?

$A$ crystal is made up of metal ions $M_1$ and $M_2$ and oxide ions. Oxide ions form a $ccp$ lattice structure. The cation $M_1$ occupies $50 \%$ of octahedral voids and the cation $M_2$ occupies $12.5 \%$ of tetrahedral voids of the oxide lattice. The oxidation numbers of $M_1$ and $M_2$ are,respectively:

What is the total volume occupied by atoms in a face-centered cubic $(FCC)$ unit cell of a metal?

Potassium fluoride $(KF)$ has a $NaCl$ type structure. If the edge length of the unit cell is $a$,what is the distance between $K^+$ and $F^-$ ions?