Step 1: Total number of players = 3 × 5 = 15 players.
Step 2: Total sum of ages for each team:
Step 3: Total sum of ages for all players = 115 + 125 + 150 = 390.
Step 4: Average age of all players = 390 ÷ 15 = 26.
Conclusion: The average age of all players is 26.