For each part of question $54,$ use your algorithm from question $53$ to find the optimal schedule for talks so that the total number of attendees is maximized.
- $20, 10, 50, 30, 15, 25, 40.$
- $100, 5, 10, 20, 25, 40, 30. $
- $2, 3, 8, 5, 4, 7, 10. $
- $10, 8, 7, 25, 20, 30, 5.$