Question

How many unit cubes were removed from the solid on the left to obtain the solid on the right?

• A. $3$
• B. $4$
• C. $5$
• D. $6$

Answer 1

Answer: (B)

$4$

Here, we can observe that the actual dimensions of the second figure is same as first figure.

But, it can be clearly seen that some of the blocks are removed from the first to make second solid.

So, as we can see, a volume of $2\times 1\times 2=4$ cubic cm is removed from the first solid to make the second one.

Now, Total Volume removed $=4$ cubic cm

Volume of one cube $=1$ cubic cm

Thus, no. of cubes removed $=\frac{4}{1}=4$ cubes

Hence, $4$ is the correct no. of cubes removed.