The volume of any rectangular prism shaped object whose dimensions are
a by
b by
c is given by the formula

.
The bottom tier has the shape of a rectangular prism with dimensions 18 by 12 by 8 cm, thus the volume of the bottom tier is

(cubed cm).
The middle tier has the shape of a rectangular prism with dimensions 12 by 8 by 6 cm, thus the volume of the middle tier is

(cubed cm)
The top tier has the shape of a rectangular prism with dimensions 4 by 4 by 4 cm, thus the volume of the top tier is

(cubed cm)
The volume of the entire cake is the sum of the volumes of each tier, thus:

(cubed cm)
Answer:
