Volume of a cube is length x width x height. I recommend to find the volume of the two separate figures then add it. For the one on the test it if 8 x 14 x 10 which is 1120cm3 and the one on the right is 8 x 10 x 10 which is 800cm3. 1120cm3 + 800cm3 is 1920cm3 total volume of the figure.