You have a cube of ice floating in a glass of water. The question is what fraction of the ice will be above the water line? Assume that the ice is not bobbing.

Most of you have probably heard the answer to this before. But please provide a proof or solution, along with your assumptions.

The question never mentions one must not add in half cup of ice cubes into the cup.

The question only mention a ice cube and that ice cube can be assumed that it is one of many ice cubes that you add into the cup.  For instance, there are many added.  Some sink & some float.  Answer is still uncertainty and unpredictable.

Thanks