Oh, wasn’t aware of the AM-GM inequality, not that I would have solved it had I known. Looks like it’s frequently used in Olympiad questions as it’s the first item listed in a study guide google found for olympiads. Met a guy who’d excelled in those, was very smart, but nothing extraordinary when it came to more general/abstract math (I’m prob jealous, still)
Discussion
If you want a hint, try finding a way to apply AM-GM twice.
I read the solution already, but that’s a solid hint. Kinda glad to have learned of the AM-GM ineq, feels like something I could have used once or twice in the past
Btw, your write up on CTs is great. Been making some reading stops along the way of going through 02bp’s paper (and related things).