Answer:
The total volume, in cubic feet, of the three boxes is 144 cubic feet.
Chain of thought:
1. Volume = base x height
2. Box 1: Volume = 16 sq feet x 3 feet = 48 cubic feet
3. Box 2: Volume = 16 sq feet x 3 feet = 48 cubic feet
4. Box 3: Volume = 16 sq feet x 5 feet = 80 cubic feet
5. Total Volume of three boxes = 48 + 48 + 80 = 144 cubic feet