A cube of side 3 inches has a cube of side 1 inch cut from each corner. A cube of side 2 inches is then inserted in each corner. What is the number of square inches in the surface area of the resulting solid?
Original surface area = 3 x 3 * 6 = 54 in^2
Remove 8 x 3 in^2 = 24 in^2
add the 2 inch cubes surface area 2x 2 x 6 x8 = 192 in ^2
less the surface area covered by putting in the corners 3 x 8 = 24 in^2
54 -24 + 192 - 24 = 198 in^2