SOLUTION
Given the question in the image, the following are the solution steps to answer the question.
STEP 1: Write the volume of the given structure

STEP 2: Get the height of the cube
The volume represents the total number of cubes needed to build the structure and it is 24 inches cubed. It can be seen from the image that, the base shown below has 6 cubes which is a 3 by 2 dimension.
To get the height means that number of time we are going to have an equal number of cubes arranged on the base. This will be gotten by:


Hence, the height will need to be 4 cubes