It turns out ... Math students learn about Ramsey problems early on, so r(4,t) has been on Verstraete's radar for most of his professional career. In fact, he first saw the problem in print ...

Well, maybe. For now, you can take a crack at the hardest math problems known to man, woman, and machine. For more puzzles and brainteasers, check out Puzzmo. In September 2019, news broke ...