I've never managed to solve one But, then again, that's probably because I only spend about 5 minutes on them, at the most.
5 minutes or so whilst watching a movie and talking in the IRC, haven't actually tried when I'm not doing something else. Its a good stress reliever.
Hmm, around a minute fifteen. S'been a while since I last picked it up, and I'm stuck using the layers algorithms as the other one just boggles my mind but..
i know a guy was in my school that could do it in around 10 secs... hes like top canadian and top10 in the world, im not sure lol it will take me probably a year to do it lol no patience at all whatsoever