Answer:
<em>5</em><em> players participated in the tournament.</em>
Step-by-step explanation:
In a small chess tournament, 20 matches were played.
Let us assume that n number of players participated in the tournament
As in each game 2 players play, so the number of ways they can play is,
As they played 2 games with every other participant in the tournament.
So the total number of games is,
But it is given to be 20, so
As , so we get n=5.
Therefore, 5 players participated in the tournament.