Hint 1.4
The displaced water is the water pushed out of the way by the object in the water. If the object is completely submerged, the volume of the displaced water is then entire volume of the object. If the object is floating the volume of the displaced water is the volume of that part of the object that is below the water surface. In this problem the displaced water is the area of the top (or bottom) surface multiplied by H-h.