Answer: The volume of the composite figure is 140 in³.
Step-by-step explanation: We are given to find the volume of the composite figure shown in the diagram.
The figure is composed of two geometrical figures :
(A) A cuboid of dimension 3 in. by 4 in. by 7 in.
So, the volume of the cuboid will be

(B) A rectangular pyramid of height 8 in. and base of dimension 3 in. by 7 in.
So, the volume of the pyramid will be

Therefore, the volume of both the cuboid and pyramid is

Thus, the required volume of the composite figure is 140 in³.