480 inches cubed. Just multiply the units of each prism together. The larger one will be 8x10x5=400, and the smaller prism will be 4x4x5=80. Just add them together and that will be your volume. Remember, prisms are always cubed.
The answer should be 480 cm^3. I see the figure as two separate rectangles. Thus, following the formula (b*h*w) the equation can be set as (8*10*5)+(4*4*5)=480
