I started playing the game Lost Dimension recently, and will reproduce the logic problem of the game here. Note that this would therefore have some implied spoilers from that game, although not beyond the first few hours of the game.
There are P (P <= 10) people, N of whom are suspicious. For each trial, you choose 5 people, and learn how many of them are suspicious (e.g. 'Of these 5 people, 2 of them are suspicious'). P and N are known.
What strategy can be used to perfectly identify all N suspicious people in the smallest possible number of trials?
Bonus: What if N is not known?