We know there are 55 total games in the tournament so keep that in mind.
1. There are 5 left-handed players and 5 right-handed players so each left-handed player will play 5 right-handed players so there are 5*5 matches in there so it is 25.
2. Well, that would just be 4+3+2+1 left-hand only matches which will add up to 10 rounds.
3. It would be the same as the left-handed players which is 10/55 which simplifies to 2/11.
4. Anita will play 9 games so it is 9/55 which cannot be simplified.