Please help with this

Of four points are collinear, they are also coplanar

Abby is preparing fruit punch for her party. she starts with a bowl filled with liquid that has 1/2 fruit juice and 1/2 sprite, but she decides it's too fruity. so she pours out 1/4 of the liquid, and then fills the bowl up again with sprite. what fraction of the punch is now sprite?

The radius of a sphere is 3 inches. which represents the volume of the sphere?