$A = \{1, 2, 3\}, B = \{2, 3, 7\} \Rightarrow A \cup B =$

(a) $\{1, 2, 3\}$
(b) $\{1, 3, 7\}$
(c) $\{1, 2, 3, 7\}$
(d) $\{1, 2, 7\}$

Question

$A = \{1, 2, 3\}, B = \{2, 3, 7\} \Rightarrow A \cup B =$

(a) $\{1, 2, 3\}$
(b) $\{1, 3, 7\}$
(c) $\{1, 2, 3, 7\}$
(d) $\{1, 2, 7\}$

Accepted Answer

>

> [!TLDR]
> $A \cup B = \{1, 2, 3, 7\}$: the union lists every element that is in $A$ or in $B$ (or both), each written once.
>
> For sets $A$ and $B$, the union is $A \cup B = \{x : x \in A 	ext{ or } x \in B\}$ — combine both sets and remove duplicate entries.
> …

Operation	What it asks	Bucket contains
Union ( $A \cup B$ )	In either?	Everything from $A$ or $B$ (or both)
Intersection ( $A \cap B$ )	In both?	Only the overlap
Difference ( $A \setminus B$ )	In $A$ but not $B$ ?	Just the part of $A$ that doesn't touch $B$
Complement ( $A^c$ )	Not in $A$ ?	Everything outside $A$ (inside $U$ )
Symmetric Difference ( $A \triangle B$ )	In exactly one?	The two crescent-shaped parts, excluding the overlap

Q. $A = \{1, 2, 3\}, B = \{2, 3, 7\} \Rightarrow A \cup B =$

Concept understanding — Set Operations

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Q.A={1,2,3},B={2,3,7}⇒A∪B=A = \{1, 2, 3\}, B = \{2, 3, 7\} \Rightarrow A \cup B =A={1,2,3},B={2,3,7}⇒A∪B=

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Q. $A = \{1, 2, 3\}, B = \{2, 3, 7\} \Rightarrow A \cup B =$

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