1. COMP 170 L2 L15: Probability of Unions of Events l Objective: n The inclusion-exclusion principle for probability Page 1

2. COMP 170 L2 Page 2

3. COMP 170 L2

4. Example: Roll Two Dice Page 4

5. COMP 170 L2 Page 5

6. COMP 170 L2 Page 6

7. COMP 170 L2

8. Notation Page 8

9. COMP 170 L2 Page 9

10. COMP 170 L2 Example: Backpack Page 10

11. COMP 170 L2 Backpack Problem Page 11

12. COMP 170 L2 Backpack Problem Page 12

13. COMP 170 L2 Backpack Page 13

14. COMP 170 L2 Backpack Page 14

15. COMP 170 L2 2 nd event Page 15

16. COMP 170 L2 2nd event Page 16

17. COMP 170 L2 2nd event

18. COMP 170 L2 2nd event 3rd event Page 18

19. COMP 170 L2 Page 19

20. COMP 170 L2 Proof of Theorem 5.3 l See course notes