How to create AI-proof math questions?

I teach economics and math at University. I want to create problems that chatgpt can't solve. I need to take in-person (in physical lecture room) online quizzes in my courses so that grading is quick and I can randomize questions easily. But if i keep online quiz, students will use chatgpt. Can you suggest what approach to use to design the problems that can fool chatgpt?

The topics I need to test students on are calculus (single and multivariable), optimization and algebra. I mostly give short answer questions where students need to calculate something and write the Intermediate/ final answer.