Set Theory B790Ad
1. Problem: Determine the nature of the set $A = (2,4,6,8,10, \ldots)$.
- This set contains even numbers starting from 2 and continues indefinitely.
- A set with infinite elements is called an infinite set.
- Therefore, $A$ is an infinite set.
2. Problem: Find the cardinality of the set $A = (3,4,5,5,6,7,8)$.
- Cardinality means the number of distinct elements.
- Remove duplicates: $(3,4,5,6,7,8)$.
- Count elements: 6.
3. Problem: Determine the relationship between sets $L = (3,1,2)$ and $M = (1,2,3)$.
- Sets are equal if they contain the same elements regardless of order.
- Both sets have elements 1, 2, and 3.
- Therefore, $L$ and $M$ are equal sets.
4. Problem: Identify which option is a proposition.
- A proposition is a statement that is either true or false.
- "8 + 4 = 12" is a statement that is true.
5. Problem: Find the truth value of $p \lor q$ if $p$ is true and $q$ is false.
- $p \lor q$ means $p$ OR $q$.
- True OR False is True.
6. Problem: Determine the truth value of $p \lor \neg p$.
- $p \lor \neg p$ is a tautology, always true.
7. Problem: Find $A \cup B$ for $A = (1,2,3,4)$ and $B = (4,5,6,7)$.
- Union combines all unique elements.
- $A \cup B = (1,2,3,4,5,6,7)$.
8. Problem: Find the number of subsets of $A = (15,16,17)$.
- Number of subsets of a set with $n$ elements is $2^n$.
- Here, $n=3$, so subsets = $2^3 = 8$.
Final answers:
1. C. Infinite
2. B. 6
3. C. Equal sets
4. B. 8 + 4 = 12
5. B. True
6. C. True
7. None of the options exactly match correct union $(1,2,3,4,5,6,7)$
8. B. 8