Question

I understand the basics but not sure what to do with the S
Let
A={a,{a},{{a}}}
B={⌀,{a},{a,{a}}}
C={a}
Be subsets of S={⌀,a,{a},{{a}},{a,{a}}}. Find
a. A ∩ C
b. A’ ∩ B
c. (B ∪ C) ∩ A
d. {⌀} ∩ B
e. ⌀ ∩ B

Answer 1

S is going to be used in part b) because:
\(\large\rm S\setminus A=A'\)

Answer 2

Any ideas for part a) ? :)
All of the elements that show up in A `and` C?

Answer 3

{a,{a},{{a}}} u {a}

Answer 4

yeah i guess i dont get this

Answer 5

you mean {a,{a},{{a}}} `n` {a} ? :o

Answer 6

yeah sorry

Answer 7

\[\large\rm A\cap C \quad=\quad \{~\color{orangered}{a},\{a\},\{\{a\}\}~\} \quad\cap\quad \{\color{orangered}{a}\}\]

Answer 8

See what they have in common? :)

Answer 9

No, you're thinking union :O
Take stuff from either of the sets and combine it all together.

Answer 10

But also, keep in mind that we don't repeat elements, even when doing union,\[\large\rm \{a,b\}\cup \{a\}\ne \{a,a,b\}\]\[\large\rm \{a,b\}\cup \{a\}= \{a,b\}\]

Answer 11

If I draw it visually maybe it'll help.

Answer 12

ok thank you