21. Five participants of the competition became its prize winners, scoring 20, 19, and 18 points and taking first, second, and third places, respectively. How many participants won each prize place if together they scored 94 points?
21. Three prize-winning participants scored 57 points ( $20+19+18=57$ ), so the other two scored 37 points ( $94-57=37$ ). Since $37=19+18$, one of them scored 19, and the other scored 18 points. Therefore, the first place was taken by one participant, the second place by two participants, and the third place by two participants.