I have a few questions in mathematics: 1. A cereal box is 7.4 inches wide, 9.6 inches in height, and 2.5 inches deep. how many square inches are needed to make the box?

2. A classroom measures 32 ft long, 25 ft wide, and 9 ft high. the combined area of the doors and windows are 140 feet squared. what is the remaining area of the four walls in this room?

3. A steel container is shaped like a cube measuring 5.3 feet on the edge. how much steel is needed to make this container

4. A cube with 2 inch sides is placed on a cube with 3 inch sides. Then a cube with 1 inch sides are placed on the 2 inch cube. what is the surface area of the three inch cube?
please give an explanation on how you got this, thx