Test Preparation on Solid State-II-Chemistry Test Series IIT JEE-2020

A given metal crystallizes out with a cubic structure having
edge length of 361 pm. If there are four metal atoms in one unit
cell, what is the radius of one atom

The ionic radii of A+ and B- ions are 0.98x10-10m and
1.81´10-10m. The coordination number of each ion in AB is

How many unit cells are present in a cube-shaped ideal crystal
of NaCl of mass 1.00 g [Atomic masses: Na = 23,Cl = 35.5]