The answer to the maths question was: "age>21".

Make up a question that could have this as an answer.

What is the legal voting age?

PsyDAG, The answer to the questions is 'age greater than', so you wouldn't say "the legal voting age is greater than 21." What other questions do you think you could create with 'age greater than' as the answer?

Melissa

How about blackjack?

Sure, here's a question: "What is the condition that determines if someone is allowed to purchase alcoholic beverages?"