Reynaldo has a stack of blocks on his desk, as shown at right.  

1. If his stack is $2$ blocks wide, $2$ blocks long, and $2$ blocks tall, how many blocks are in his stack?

   Hint (a):

   (width)(length)(height) = the number of blocks in each stack

2. What if his stack instead is $3$ blocks wide, $3$ blocks long, and $2$ blocks tall? How many blocks are in this stack?

   Hint (b):

   See part (a) for help.

3. What if his stack contains $99$ blocks, is $3$ blocks tall, $x$ blocks long, and $y$ blocks wide? What could $x$ and $y$ be?

   Hint (c):

   Use the equation in part (a).
   Substitute $99$ into the number of blocks and $3$ into the height.
   What would $x$ and $y$ have to be in order to make this equation true?