the volume of each spherical ball is
523.6 cm^3
and the volume of the box is 60,000 cm^3
a) the answer is 60
in each 10 cm of the rectangular prism you can place one sphere. so the answer of a is (4*3*5)
b) the answer is 30
c) the answer is 31,416

d) 31,416 is 52.36% of 60,000
so the percentage of empty space is
100 - 52= 48%
good luck