In a simple cubic unit cell,how many unit cells share each lattice point located at the corner?

Which of the following has a $4:2$ coordination number structure?

If the coordination number of an element in its crystal lattice is $8$,what will be its packing structure?

$A$ cubic solid is made up of two elements $X$ and $Y$. Atoms of $X$ are present on every alternate corner and one at the center of the cube. $Y$ is at $\frac{1}{3}$ of the total faces. The empirical formula of the compound is

An ionic crystal $LiAg$ arranges in a cubic crystal system in which the coordination number of each $Li^+$ and $Ag^+$ is $8$. The crystal structure is:

Which one possesses an antifluorite structure?