Question 26
A $5\times5\times5$ cube has a $1\times1\times5$ hole cut through from one side to the opposite side, a $3\times1\times5$ hole through another and a $3\times1\times5$ hole through the third as shown in the diagram.
How many $1\times1\times1$ cubes are removed in this process?
How many $1\times1\times1$ cubes are removed in this process?