Question

let $s$ be the universal set, where:
$s = \\{1, 2, 3, ... , 28, 29, 30\\}$
let sets $a$ and $b$ be subsets of $s$, where:

set $a = \\{6, 10, 11, 16, 17, 19, 20, 21, 22, 27\\}$

set $b = \\{4, 16, 19, 21\\}$

set $c = \\{7, 10, 11, 23, 25\\}$

list the elements in the set $(a \cup b \cup c)$
$(a \cup b \cup c) = \\{ \quad \\}$
enter the elements as a list, separated by commas. if the result is the empty set, enter dne

list the elements in the set $(a \cap b \cap c)$
$(a \cap b \cap c) = \\{ \quad \\}$
enter the elements as a list, separated by commas. if the result is the empty set, enter dne

you may want to draw a venn diagram to help answer this question.
question help: video 1 video 2

Explanation:

Step1: Combine all unique elements

Combine elements from A, B, C, remove duplicates, sort them.
Elements: 4,6,7,10,11,16,17,19,20,21,22,23,25,27

Step2: Find common elements in all sets

Check elements present in A, B, and C. No such elements exist.

Answer:

$(A\cup B\cup C) = \{4, 6, 7, 10, 11, 16, 17, 19, 20, 21, 22, 23, 25, 27\}$
$(A\cap B\cap C) = \{DNE\}$