Q: A school is asked to send a delegation of 6 players selected from 6 badminton players, 6 tennis players and 5 squash players. No pupil plays more than 1 game. The delegation is to consist of at least 1, and not more than 3, players drawn from each sport. Find the number of ways in which the delegation can be selected.

The answer I was given is 9450...but I don't know how to derive it...X.x Thank you for helping!