The volume of a sphere is computed as follows:
V = 4/3*π*r³
where r is the radius of the sphere. If the diameter of the ball is 1.6 in, then its radius is 1.6/2 = 0.8 in, and its volume is:
V = 4/3*π*0.8³ = 2.14 in³
The volume of the storage unit is:
V = width*length*height
Replacing with data:
V = 10*20*8 = 1600 ft³
1 ft³ is equivalent to 1728 in³, then 1600 ft³ = 1600*1728 = 2764800 in³
Finally, the number of golf balls that fit inside of a storage unit is 2764800/2.14 ≈ 1291962 balls