Accusing people of asking "stupid questions" is a terrible idea

[Peter1986]

Clearly you've never worked in the service industry.

Actually I have - I sold packs of ice cream to people for a couple months a few summers ago (and it was very common to cover many square miles every day), and I frequently answered various questions without being a jerk, because service people are supposed to be polite to their customers.
I have also had a few job where I came in frequent contact with people who could have questions about things there, and I basically just answered their questions, like any good service person would do, that's best for everyone - they get answers to their honest questions, and nobody feels insulted in any way.

If someone feels the need to ask a question about something, then that question is important to them, and that's all that matters.
And if the answer seems "overly obvious" or whatever then that's no big deal, this can happen to anyone.
I highly doubt that you have never ever asked a question that turned out to have a simple answer.