Answer:
24 cubic cm.
Explanation:
* = multiplied by
volume = length*width*height
2*4*3 = 24
If you still don't understand, you can count the blocks, and I'm sure you will get the same number, 24. Make sure you count the blocks that are behind the other blocks, too!
The writer of this question also already gave you a hint by saying: The rectangular prism shows 4 layers with 6 cubes in each layer. That means they solved the area (length*width) already, so you only need to multiply the area by the height. So 6*4, you also end up with 24.
Hope this helps!