(Volume for a rectangular shape is length x width x height)
We can split up this 3D composite figure into two main parts (as shown in the picture I attached), and find each part’s volume before adding them together for the total volume.
Cube —> 5x5x5 —> 25x5 = 125 in^3
Rectangular Prism —> 20x5x5 —> 100x5 = 500 in^3
125 + 500 = 625
So the answer is A. 625 in^3
Hope this helped! If I was correct, I’d appreciate it if you marked my answer as Brainliest.