List of top Chemistry Questions on packing efficiency asked in AP EAPCET

Which of the following statement is not correct?

In the structure of A\(_x\)B\(_y\), cations (A) occupy all the tetrahedral voids while anions (B) form fcc lattice. What is the ratio of x and y?

What is the packing efficiency in fcc lattice?

Solid A forms bcc lattice, Solid B forms fcc lattice. If the unit cell lengths (a) of A and B are 4 and 5 Å respectively, what is the ratio of the radii of A and B?