Here are some random tasks that I quite can't wrap my head around. Instructions: There are two rule-based categories in each of these 5 puzzles, marked with either black or grey dots. To which category do the uncategorized (white-dotted) items belong and why? 

My problem with task 1 is for instance that the black-dotted items all have "Z", but if the rule is "exactly four Z", the most-right uncategorized item should be grey (it has five), but if the rule is "at least four Z" the item should be black.

Task 1
[![Task 1][1]][1]

Task 2
[![Task 2][2]][2]

Task 3
[![Task 3][3]][3]

Task 4
[![Task 4][4]][4]

Task 5
[![Task 5][5]][5]

  [1]: https://i.sstatic.net/WzZB6.jpg
  [2]: https://i.sstatic.net/mGZwO.jpg
  [3]: https://i.sstatic.net/W59Zt.jpg
  [4]: https://i.sstatic.net/SZBEb.jpg
  [5]: https://i.sstatic.net/E9hRf.jpg