1. 11.6
SETS AND COUNTING

2. A set is a well-defined collection of distinct objects.
If a set has no elements, it is called the empty set, or null set, and is denoted by the symbol

3. If two sets A and B have precisely the same elements, then A and B are said to be equal and write A = B.

4. A B U

8. A B U

9. A B U

10. A B U

11. A A U

13. Theorem Counting Formula

14. In survey of 50 people, 21 said they owned stocks, 32 said they owned bonds and 12 said they owned both stocks and bonds. How many of the 50 people owned stocks or bonds? How many owned neither?
A: person owns stock
B: person owns bonds
= = 41
= 9 owned neither