EXPLANATION:
From the question we are told that there are 20 unit cubes.
Each unit cube would measure;
[tex]\begin{gathered} length=1unit \\ width=1unit \\ height=1unit \end{gathered}[/tex]
Therefore, the volume of each cube would be;
[tex]\begin{gathered} Volume=l\times w\times h \\ Volume=1\times1\times1 \\ Volume=1unit^3 \end{gathered}[/tex]
However, with 20 unit cubes all stacked on top of one another, the height of the entire stack/tower would now be 20 units. Note that the length and the width remains unchanged.
Therefore, the volume of the tower would be calculated as follows;
[tex]\begin{gathered} Volume=l\times w\times h \\ Volume=1\times1\times20 \\ Volume=20units^3 \end{gathered}[/tex]
ANSWER:
Option C: 20 cubic units
