Answer: 27 players will be notified during the third round of calls.
Step-by-step explanation:
In case the game is canceled, the coach calls three players. This means that if each of these three players call three more players, the number of players that will be notified during second round of call would be
3 × 3 = 9 players.
If each of these nine players call three more players, the number of players that will be notified during third round of call would be
9 × 3 = 27 players.
The total number of players that would have been notified is
3 + 9 + 27 = 39 players
