Answer:
Step-by-step explanation: Top Box:
A = height x length x width
A = 10 x 40 x 20
(the height is 10 because it is equal to the tallest height minus the shorter height)
A = 8000 in. cubed
Bottom Box:
A = height x length x width
A = 20 x 60 x 20
A = 24000 in. cubed
Total Volume = 24000 in. cubed + 8000 in. cubed = 32000 in. cubed