Puzzles

Agilist, #24, did I get it right?

Added 2 minutes later

Ataman, I commented on my answer to #28 there.

Regarding division by zero. Okay, okay. But the problem specifically required a specific number ;)

I've already seen it, everything is correct.

So, the problem specifically mentions a specific number (and in general, it's not that important; you can assume that division by zero is not allowed).