I apologize for posting in English. I have no excuse for not being fluent in Spanish, but I'm not. Snark is the only troll free math discussion group of which I am aware.
1) A, B and C are sharing a pizza. Each will make 1 cut from the center of the pizza to it's circumference. A will make his cut first, followed by B, then C. A will then select the slice he wants, followed by B and C. C hates B and will make his cut so as to minimize B's share of the pizza, even that results in less pizza for him. B is aware of that. How should B make his cut to maximize his share of the pizza?
2) Same scenario as above, except that there is no restriction on B's cut other than that it must be smooth (has a differential defined at all points) and that it be made without lifting the knife.
From Google Translator, slightly edited to remove the more ridiculous errors: (Desde Google Traductor, con pequeñas modificaciones para eliminar los errores más ridículos)