Final answer:
To find the volume of the suitcase, multiply its length, width, and thickness.
Step-by-step explanation:
To find the volume of the suitcase, you need to multiply its length, width, and thickness.
The width of the suitcase is 12 inches, which can be denoted as 12 in.
The length of the suitcase is 1.5 feet, or 18 inches, which can be denoted as 18 in.
The thickness of the suitcase is 4 inches, which can be denoted as 4 in.
Now, multiply the length, width, and thickness together to find the volume:
Volume = length x width x thickness = 18 in. x 12 in. x 4 in.
Volume = 864 cubic inches.