Answer:
A. 140 cubic inches
Explanation:
The total volume is the volume of the rectangular prism at the bottom plus the volume of the pyramid on top.
The volume of the prism is width times length times height.
V = wlh
V = (3)(7)(4)
V = 84
The volume of the pyramid is one third the area of the base times the height.
V = ⅓ Ah
The base of the pyramid is a rectangle. Its area is the width times length. The height of the pyramid is the total height minus the height of the prism.
V = ⅓ (3)(7)(12−4)
V = 56
So the total volume is:
V = 84 + 56
V = 140