Each of the 8 edges of a pyramid with a square base is 4 inches long and each edge of a cube is 4 inches long. The base of the pyramid is set on one face of the cube so that their vertices coincide. The new solid that is formed has how many faces?
The cube has 6 faces. The pyramid has 5 faces. When you put them together, then you lose one face from each (the bottom of the pyramid and the top of the cube become part of the inside of the new solid), and end up with 5 + 4 = 9 faces.