When professors keep repeating questions that clearly no one can answer

"How can you calculate this value?...... How can you calculate this?.... come on, how can you calculate this?..... This isn't a hard question, how can you calculate this?" Dude. Stop. Please. I promise if no one answered by the 2nd time, that's because no one knows the answer. Just accept it and move on, no one gains anything from you repeating it 5 times. This is a common occurance in my seminars and it's annoying every single time.