3 ms·
I linked to another related puzzle elsewhere in this discussion: there appears to be a solution for 9 cylinders of infinite length but different radii. It's no
by lotharbot 13y ago
I linked to another related puzzle elsewhere in this discussion: there appears to be a solution for 9 cylinders of infinite length but different radii. It's not clear what's known about the case of 10 cylinders.
So there are known solutions for 5 coins, 7 identical infinite cylinders, 7 identical finite cylinders (maybe more), and 9 different infinite cylinders.
- darkmighty 13y agoIs there an example of a similiar non-trivial problem for which there is an inexistance proof? I'm not a mathematician so I have a hard time picturing a way of proving this sort of thing when the number of objects is "tricky" (not too high, not too low), apart from simply showing a counterexample.
- Strilanc 13y agoHow about the fact that there are no more than 5 platonic solids [1]? (See the proof in the article) 1: http://en.wikipedia.org/wiki/Platonic_solid http://en.wikipedia.org/wiki/Platonic_solid