I've started answering all calls from numbers I don't recognize like this:
"Wow Machine Radio, you're caller number 43 and you are on the air, live right now! Go ahead with your answer to the trivia question, caller! Caller?"
At that point, they either hang up or they ask, "What was the question again?"
When they ask, that I say, "Ohhh, I'm sorry, 'what is the question again' is a popular answer today, but it is incorrect, try again with tomorrow's trivia question!"