Let [tex]$U$[/tex] be the universal set, where:
[tex]\[ U=\{1,2,3,4,5,6,7,8,9,10,11\} \][/tex]

Let sets [tex]$A$[/tex], [tex]$B$[/tex], and [tex]$C$[/tex] be subsets of [tex]$U$[/tex], where:
[tex]\[
\begin{array}{l}
A=\{1,2,4,7,11\} \\
B=\{1,3,4,6,7,9,11\} \\
C=\{1,5,8,11\}
\end{array}
\][/tex]

Find the following:

1. List the elements in the set [tex]$A^{\prime} \cup \emptyset$[/tex]:
[tex]\[ A^{\prime} \cup \emptyset = \{ \}
\][/tex]
[tex]\[ \square \text{ Enter the elements as a list, separated by commas. If the result is the empty set, enter DNE.} \][/tex]

2. List the elements in the set [tex]$B \cap C$[/tex]:
[tex]\[ B \cap C = \{ \}
\][/tex]
[tex]\[ \square \text{ Enter the elements as a list, separated by commas. If the result is the empty set, enter DNE.} \][/tex]

3. List the elements in the set [tex]$A^{\prime} \cup B$[/tex]:
[tex]\[ A^{\prime} \cup B = \{ \}
\][/tex]
[tex]\[ \square \text{ Enter the elements as a list, separated by commas. If the result is the empty set, enter DNE.} \][/tex]

4. List the elements in the set [tex]$(C \cap B) \cap A^{\prime}$[/tex]:
[tex]\[ (C \cap B) \cap A^{\prime} = \{ \}
\][/tex]
[tex]\[ \square \text{ Enter the elements as a list, separated by commas. If the result is the empty set, enter DNE.} \][/tex]

You may want to draw a Venn Diagram to help answer this question.



Answer :

Let's solve this step by step.

Given the universal set and the subsets:
[tex]\[ U = \{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11\} \][/tex]
[tex]\[ A = \{1, 2, 4, 7, 11\} \][/tex]
[tex]\[ B = \{1, 3, 4, 6, 7, 9, 11\} \][/tex]
[tex]\[ C = \{1, 5, 8, 11\} \][/tex]

### Step 1: Find [tex]\( A' \)[/tex] (the complement of [tex]\( A \)[/tex])
The complement of [tex]\( A \)[/tex] in the universal set [tex]\( U \)[/tex] is given by the elements in [tex]\( U \)[/tex] that are not in [tex]\( A \)[/tex]:
[tex]\[ A' = U \setminus A = \{1, 2, 4, 7, 11\} = \{3, 5, 6, 8, 9, 10\} \][/tex]

### Step 2: Find [tex]\( A' \cup \emptyset \)[/tex]
The union of any set with the empty set is the set itself:
[tex]\[ A' \cup \emptyset = A' = \{3, 5, 6, 8, 9, 10\} \][/tex]

### Step 3: Find [tex]\( B \cap C \)[/tex]
The intersection of [tex]\( B \)[/tex] and [tex]\( C \)[/tex] is the set of elements that are in both [tex]\( B \)[/tex] and [tex]\( C \)[/tex]:
[tex]\[ B \cap C = \{1, 3, 4, 6, 7, 9, 11\} \cap \{1, 5, 8, 11\} = \{1, 11\} \][/tex]

### Step 4: Find [tex]\( A' \cup B \)[/tex]
The union of [tex]\( A' \)[/tex] and [tex]\( B \)[/tex] includes all elements that are in either [tex]\( A' \)[/tex] or [tex]\( B \)[/tex]:
[tex]\[ A' \cup B = \{3, 5, 6, 8, 9, 10\} \cup \{1, 3, 4, 6, 7, 9, 11\} = \{1, 3, 4, 5, 6, 7, 8, 9, 10, 11\} \][/tex]

### Step 5: Find [tex]\( (C \cap B) \cap A' \)[/tex]
First, find the intersection of [tex]\( C \)[/tex] and [tex]\( B \)[/tex]:
[tex]\[ C \cap B = \{1, 5, 8, 11\} \cap \{1, 3, 4, 6, 7, 9, 11\} = \{1, 11\} \][/tex]
Next, find the intersection of this result with [tex]\( A' \)[/tex]:
[tex]\[ (C \cap B) \cap A' = \{1, 11\} \cap \{3, 5, 6, 8, 9, 10\} = \emptyset \][/tex]

So, the final answers are:
1. [tex]\( A' \cup \emptyset = \{3, 5, 6, 8, 9, 10\} \)[/tex]
2. [tex]\( B \cap C = \{1, 11\} \)[/tex]
3. [tex]\( A' \cup B = \{1, 3, 4, 5, 6, 7, 8, 9, 10, 11\} \)[/tex]
4. [tex]\( (C \cap B) \cap A' = \emptyset \)[/tex]

Here they are, arranged with appropriate formatting:
[tex]\[ A' \cup \emptyset = \{3, 5, 6, 8, 9, 10\} \][/tex]
[tex]\[ B \cap C = \{1, 11\} \][/tex]
[tex]\[ A' \cup B = \{1, 3, 4, 5, 6, 7, 8, 9, 10, 11\} \][/tex]
[tex]\[ (C \cap B) \cap A' = \emptyset \][/tex]