Even if a question appears "stupid", it deserves a serious answer. Questions that are obviously frivolous are routinely removed from the site. What is obvious to everyone is that "stupid" answers come from those with little or no knowledge to share.
You should NOT answer a question with "that is stupid", or with any response that is not a relevant, understandable answer to that question. "I don't know" is also not an answer, because the question is not to you individually. Let someone answer who knows.
Please be aware that continually posting nonsense, or non-answers, may result in restrictions on the use of the site.