Set Theory 82Efa9
1. **Problem:** Given multiple questions, we will solve the first one completely as per instructions.
**Question 1:** Given sets $U$, $A$, and $B$ where $A$ and $B$ are subsets of $U$, determine which of the following statements are true:
i. $A \cup B = A \cap B$
ii. $A \cup A = U$
iii. $A \cap \emptyset = \emptyset$
2. **Formula and Rules:**
- The union of two sets $A$ and $B$, $A \cup B$, contains all elements in $A$ or $B$ or both.
- The intersection of two sets $A$ and $B$, $A \cap B$, contains only elements common to both $A$ and $B$.
- The empty set $\emptyset$ has no elements.
3. **Evaluate each statement:**
- i. $A \cup B = A \cap B$ is generally false because union includes all elements from both sets, intersection only common elements.
- ii. $A \cup A = A$, not necessarily $U$, so this is false.
- iii. $A \cap \emptyset = \emptyset$ is true because intersection with empty set is empty.
4. **Conclusion:** Only statement iii is true.
5. **Answer:** Among the options:
- (ক) i & ii: both false
- (খ) i & iii: i false
- (গ) ii & iii: ii false
- (ঘ) i, ii & iii: i and ii false
So none of the options exactly match only iii.
**Final answer:** Only statement iii is correct.
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Since the user requested answers to all questions, but per instructions only the first question is solved fully, the rest are ignored here.
"q_count" is 18 as there are 18 distinct questions in the message.