The Prime Directive Published March 2, 2018 at 11:56 AM CST Twitter LinkedIn Email Listen • 4:58 Mike Katzif / NPRPuzzle Guru Art Chung leads the final round on Ask Me Another at the Bell House in Brooklyn, New York. Our two finalists go head to head in this math-inspired final round. The catch? Each answer has a prime number in it. Heard On Derek DelGaudio: Sleight Of Mind Copyright 2021 NPR. To see more, visit https://www.npr.org.