Answer:
The answer should be 210 unit cubes.
Step-by-step explanation:
The volume of a rectangular prism is given by the following expression:
[tex]volume = length*width*height[/tex]
In words, it is the product of its edge lengths. If the prism was packed with 210 unit cubes, then this must be equal to its volume, so by multiplying the edge lengths the result should be equal to 210 unit cubes.