Geometry problem?

The answer should be 692. The formula for the surface area of a rectangular prism is 2ab + 2bc +2ac. So..2(15)(8) + 2(8)(11) + 2(11)(15) = 746. BUT, there are those six rectangular holes, which are 3 X 3 each. So each of them has a surface area of 9, so 6 X 9 = 54. Subrtract that from 746 and you will get 692. Oh, and add the surface area of the imbedded rectangle holes, so that will give you 3 * 11 * 4 which will give you 132. And there is 3 of those, so 132 * 3= 396. Add taht to the 692 and you will get 1088 cm^3.