120 inches cubed (^3)
To find the volume of a rectangular prism, the formula is base area • height. We just have to solve this problem.
The two sides of the base 8 and 5. 8 • 5 = 40, so the area of the base = 40.
Then, the height is 3. 40 • 3 = 120, so the volume is 120 inches^3