Analogue of "Is the Pope Catholic?"

Question

In English, one way to respond to a question where the answer is obviously yes is to ask back "Is the Pope Catholic?" What is a Russian analogue, i.e., a conventional question-as-reply for which the answer is clearly affirmative?

A good answer to this question should work, for instance, in both of the following situations:

1) Replying to "I saw Ivan on the bus to the airport. Is he traveling somewhere?"

2) You are a chemist and someone says to you "There is a username on chemistry.stackexchange that is your first initial and last name. Is that you?"

Answer 1

Usually something like "А как ты думаешь?" (And how do you think?) with a slight accent pointing that the speaking person actually wonders how else one can think on such simple question.

But if you mean, if there are more mocking ways to answer some stupid questions, I should say, it depends. But, anyway, in a strictly affirmative form, not in a question-as-reply one. For example, teenager-like slang "Ясен пень!" (Clear stump!) or Odessa-like "Или" (Or).

Answer 2

Ещё как! (Ещё какой, ещё какие etc.)

- Твой кот - хулиган?
- Ещё какой!

Answer 3

A good answer to your both cases could also be:

Что за вопрос?

It can mean "Absolutely! You shoudn't have been asked" or that the answer to a question you have just been asked is obviously 'yes'.

Answer 4

More or less neutral way:

Сам[а]-то как думаешь?

Meaning:

What do you think?

If you're irritated by blatantly banal or unpleasant question, you could reply with a statement having opposite meaning:

— Как думаешь, в этом месяце опять задержат зарплату?

— Нет, блять, премию дадут! Ты продажи-то видел?

Meaning:

— Will the salary get delayed again this month, what do you think?

— Delayed?! No, you'll get a fucking bonus! Have you seen the sales?

(Of course, nobody expects the salary to be paid in time, let alone the bonus)