The remarkable fact that virtually all of mathematics can be formalized within ZFC, makes possible a mathematical study of mathematics itself. Thus, any questions about the existence of some mathematical object, or the provability of a conjecture or hypothesis can be given a mathematically precise formulation. This makes metamathematics possible, namely the mathematical study of mathematics itself. So, the question about the provability or unprovability of any given mathematical statement becomes a sensible mathematical question. When faced with an open mathematical problem or conjecture, it makes sense to ask for its provability or unprovability in the ZFC formal system. Unfortunately, the answer may be neither, because ZFC, if consistent, is incomplete.