I need help with this question: One thousand cubes are arranged to form
a large cube. All the surfaces of the large cube are painted. What 
fraction of the cubes are not painted at all?

Since there are 1000 blocks, and since the cube root of 1000 is 10,
the large cube is 10x10x10. If we take away the outer shell of painted 
blocks, the only ones which are painted, there will be a 8x8x8 cube left.
(Remember out of each face we must take off the laft row and and the right
row of blocks, that's why there are 2 less than 10 on each side).

So the answer is  =  = 

Edwin