Did you solve it? Are you a match for the dinkiest mag in maths?

The answers to today’s problems

Earlier today I posed four puzzles from the Hyde Park Math Zine, a maths fanzine from Austin, Texas. Here they are again with solutions.

1. Ring it

I heard two new ‘invisible’ speakers that give new meaning to the idea of a ‘wall of sound’ — and they’re good enough that I’d use them for hi-fi or home theater