Hexagonal close packed arrangement of ions is described as

The correct option for the number of tetrahedral and octahedral voids in a hexagonal primitive unit cell is:

$A$ two-dimensional solid pattern formed by two different atoms $X$ and $Y$ is shown below. The black and white squares represent atoms $X$ and $Y,$ respectively. The simplest formula for the compound based on the unit cell from the pattern is

What is the full form of $fcc$?

Which of the following is the correct order of packing efficiency?

How much part of an atom occupies each corner of a $bcc$ unit cell?