Question 27
A $9\times9\times9$ cube is composed of twenty-seven $3\times3\times3$ cubes. The big cube is “tunneled” as follows: First, the six $3\times3\times3$ cubes which make up the center of each face as well as the center $3\times3\times3$ cube are removed as shown. Second, each of the twenty remaining $3\times3\times3$ cubes is diminished in the same way. That is, the center facial unit cubes as well as each center cube are removed. The surface area of the final figure is
