The point on a phase diagram where the solid state, the liquid state, and the gas vapor state can coexist is a) the triple point b) the pressure point c) the critical point d) the absolute zero point

A4.86 g piece of metal was placed in a graduated cylinder containing 15.5 ml of water. the water level rose to 17.3 ml. what is the density of the metal. i need the steps of how to solve it to so i can use a formula to work out other problems.