¿A que no puedes comer solo uno?

Question

This is the slogan on Sabritas (the Mexican equivilent of Lay's Potato Chips) In fact, I think it is owned by Lay's. But here is the question and I do not know the answer. What is the slogan saying? I think the "A" is the personal A. And the "A que" is a form of who. But then why is it puedes and not puede. If it was puede than I get "Who can eat just one?"

So let's have some alternative ideas about this one and some expert (native speaker) help as well.

Excellent question! - annierats, Aug 8, 2012

Answer 1

The English version is "Bet you can't eat just one."

Explained here!

What does "a que no puedes" mean?

Good question, I hope I can remember it the next time I see it.

Wow. Thanks. - gringojrf, Aug 8, 2012

An answer by the legendary Lazarus, no less. Thanks amaken! - annierats, Aug 8, 2012

Answer 2

Interesting! I haven't seen this before.

With "qué" the meaning is a too strange: "To what can't you?" --Lazarus

Nice on to remember.