we know that
[volume of a cylindrical salt shaker]=pi*r²*h
r=2 cm
h=7 cm
[volume of a cylindrical salt shaker]=pi*2²*7---> 87.92 cm³
[volume of the box]=b²*h
b=4 cm
h=8 cm
[volume of the box]=4²*8---> 128 cm³
[the volume of air in the box outside the salt shaker]=128-87.92--> 40.08 cm³
the answer is
the volume of air in the box outside the salt shaker is 40.08 cm³