Which statements about this prism partially packed with unit cubes are true? Check all that apply.

The middle layer of cubes is missing 7 unit cubes.
There are 9 unit cubes stacked in the prism.
There are 7 unit cubes that are hidden from view inside the prism.
The volume of the prism can be found by because there are 12 cubes in each layer and there are 3 layers of cubes.
The volume of the prism can be found by doubling the number of cubes in the prism because it is half full.

We have that the dimensions are:

height = 3

length = 3

width = 4

so in each layer of cubes, we have 3*4 = 12 cubes, and we have 3 layers.

1) The middle layer of cubes is missing 7 unit cubes.

In this layer, we have 5 cubes, and in each layer, we should have 12.

12 - 5 = 7

so this statement is true.

2) There are 9 unit cubes stacked in the prism.

Only in the bottom layer, we have 9 cubes, 5 in the second and 2 in the third one, a total of 16 cubes. this statement is false.

3) There are 7 unit cubes that are hidden from view inside the prism.

We have 16 cubes inside, and we can see 9 of them, so the ones we can not see are:

16 - 9 = 7

This statement is true

4) The volume of the prism can be found by because there are 12 cubes in each layer and there are 3 layers of cubes.

This is true, the volume of the prism is equal to 3*12 = 36 cubes

5) The volume of the prism can be found by doubling the number of cubes in the prism because it is half full.

inside the prism, we have 16 cubes, and the full prism would have 36 cubes, so it is not half full, this statement is false.