Answer to the puzzle and the next one
Divide a circle into 12 congruent pieces, with equal size and same shape, such that all pieces never meet. It's ok for pieces to be next to each other. But all of them cannot meet at the same point. So you cannot cut the circle in 12 pizza slices as they all meet at the center. This is more visual. Have fun. I first tried doing this with paper. But I was able to get it very quickly after deciding to close my eyes.
BTW, we have posted a very small collection of tech talks given here at Google on, you guessed it, Google Video.