Is coincidence mathematically unlikely

I was just wondering, is coincidence mathematically unlikely, likely or impossible? My guess was unlikely but I dont know. Any help would be great

When we use the term "coincidence", it's generally something we consider unlikely.

If we say "I bumped into Pete by coincidence", then that's something that was unlikely. If it were likely, there is probably some *reason* that it's likely, which means it's no longer coincidence. If it were impossible, it would never happen!