English Experts

[Simon Vasconcelos]

Alguém faz uma pergunta e você não sabe respondê-la. Então, você fala: Agora, você me pegou.

[Lia Teixeira]

Now you caught me.

[pondedaniel]

eu diria: that's a million dollar question!

[pondedaniel]

complementando:

the sixty-four-thousand-dollar question (informal) also the million-dollar question (informal)

an important or difficult question which people do not know the answer to

Ex: So will she marry him or not? - that's the sixty-four-thousand-dollar question.

http://idioms.thefreedictionary.com/dollar

[Thomas]

(I cannot answer your question. I do not know the answer.)
Now you got me.
You got me on that.
Darned (dang, damn) if I know.