Answer:
276in³
Explanation:
First, we can separate this into two separate rectangular prisms. We can add their volumes to get the total volume. I have separated the prisms by the light green lines, as shown in the picture.
For the top one, we have a length of 5 in , width of 3 in, and height of x in. We know that the total height is 10 in, and the bottom height is 6. The top difference is the difference of those two heights, or 10-6= 4 = x. Therefore, the volume of the top prism is 5 in* 3 in* 4 in = 60 in³
For the bottom prism, we have a length of 12 in, height of 6 in, and width of 3 in (this is the same, as the 3in from the top prism matches with the width of the of the bottom prism), making our volume 12 in * 6 in * 3 in = 216 in ³.
We can then add 216 in ³ and 60 in³ to get 276in³ as our total volume