Answer:
I didn't know what is answer
The volume of the box when it's filled to 3 inches deep is 12×8×3 = 288 in³
The box is filled up to 1.5 inches from the top, that means the box is filled only
3-1.5 = 1.5 inches deep
The volume of the box when it's filled to 1.5 inches deep is 12×8×1.5 = 144 in³
The number of flours saved is 288 - 144 = 144 in³
Here is the answer. I tried to send it vertically but I will send it horizontally again this time. Let me know if it is uncomfortable to see. Feel free to ask me!