Responding to a poor question

Solution 1:

The literal, direct translation is the English idiom: "ask a stupid question, get a stupid answer".

Or, as we say in computer science: garbage in, garbage out.

Solution 2:

'The pot calling the kettle black' is a more general proverb of this type. In this context it would imply 'who are you to say my answer is poor, when you've just asked such a poor question?'

My father always says 'a stupid question deserves a stupid answer', but this probably isn't what you're looking for!

Solution 3:

An idiom that does not apply literally, but may come close to the spirit of your phrase, is you get what you pay for.  Wiktionary says that this is

Primarily used to denigrate inexpensive goods as naturally inferior

and lists you pays your money and you takes your choice under the See also heading, although this is grammatically incorrect and of dubious relevance.

Solution 4:

Tit For Tat

Wikipedia formally defines "tit for tat" as an English saying meaning "equivalent retaliation".

It is also a highly effective strategy in game theory for the iterated prisoner's dilemma. The strategy was first introduced by Anatol Rapoport in Robert Axelrod's two tournaments, held around 1980. Notably, it was (on both occasions) both the simplest strategy and the most successful in direct competition.

An agent using this strategy will first cooperate, then subsequently replicate an opponent's previous action. If the opponent previously was cooperative, the agent is cooperative. If not, the agent is not. This is similar to superrationality and reciprocal altruism in biology.

Therefore, following the last paragraph quoted above, "tit for tat" can be, broadly speaking, applicable to the situation you describe in your question-

...used as a reply to a person who complaints about a poor answer given to his/hers poor question. It says that the quality of the answer is in relation to the quality of the question.

The FreeDictionary.com provides several definitions of this phrase-

• Repayment in kind, as for an injury; retaliation.
• an equivalent given in return or retaliation; blow for blow
• Probably borrowed from Dutch tip for tap, "blow for blow."

I would say all of them seem to fit in well with the situation you have in mind.