Erdős problem 654
If planar points have no four concyclic, must some point determine distinct distances? Failing that, can one always force more than ?
Sources
Retained excerpts/
VibeMathed
Retained source excerpt
If $n$ planar points have no four concyclic, must some point determine $(1 - o(1))n$ distinct distances? Failing that, can one always force more than $(1/3 + c)n$?
Open exact source location