I love setting pub/trivia quizzes. I like to throw in some current affairs questions at the last minute, see how much attention people pay to the news. When I’m participating in one, I like questions about nature and geography. Sports and TV questions kill me.
Here’s my current favourite. “In terms of the frequency of light radiation that it emits, what colour is our Sun?” It’s actually green.
With a question like that you have to phrase it very carefully to avoid ambiguity, you can’t just say “What colour is the Sun?” because that depends on how you measure it. Visually, it’s white. Viewed on the horizon, it’s orange. It might not even be clear which sun you’re referring to.