How many total constituent particles are present in a simple cubic unit cell?

In a face-centered cubic arrangement of atoms $A$ and $B$,atoms $A$ are at the corners of the unit cell and atoms $B$ are at the face centers. If one atom $A$ is missing from one corner of the unit cell,what is the simplest formula of the compound?

An alloy of copper,silver,and gold is found to have copper atoms in an $fcc$ lattice. If silver atoms occupy the edge centers and gold atoms are present at the body center,what is the formula of the alloy?

$A$ binary compound $(A^{+} B^{-})$ has a zinc blende structure where $B^{-}$ ions form the lattice and $A^{+}$ ions occupy $25\%$ of the tetrahedral voids. What is the formula of the compound?

Gold has a face-centred cubic $(fcc)$ lattice with an edge length of the unit cube of $407 \ pm$. Assuming the closest packing, the diameter of the gold atom is .............. $pm$.

$A$ compound contains $Ca, Ti$ and $O$ elements. If $Ca^{2+}$ ions are at the corners of the cube,$Ti$ ions are at the body center,and $O^{2-}$ ions are at the face centers,then the molecular formula of the compound and the oxidation state of $Ti$ are respectively ........