Answer:
875 ft^3
Explanation:
Pick them apart starting at the bottom. The formul used is V=lwh
Starting at the bottom we have we have a sqare of 5 ft = 5ft^3= V = 125 ft^3
Then we have a rectangular prism: 5 x 5 x 20 = V = 500 ft^3
Third we have 5 x 5 x 10 = V = 250 ft3
125+500+250 = 875 ft^3