correct me if I'm wrong but on the volume sphere and cube question:
if the lengths of the cube were 4.5, then they have to be in the upper bound (4.55cm)
therefore for maximum spheres, the radius of the spheres is in the lower bound (3mm so 2.5mm)
and convert mm into cm by dividing by 10 so 0.25cm.
then find volume of cube (4.55) cubed which is 94.196375, and the volume of the sphere (4/3 pi r cubed) so 0.06544984695. Then its 94.196375 divided by 0.06544984695 which equals 1439....