Question

Suppose U = {1,2,3,4,5,6,7,8,9,10} is the universal set and Q = {3,6,9} What is Q?

Answer 1

What is Q? Well they gave it. Do they want Q or Q compliment?

Answer 2

Q compliment

Answer 3

Just take all the numbers in U set that aren't in Q set.

Answer 4

You can do it.

Answer 5

Still confused?

Answer 6

Very much so

Answer 7

Oh! I understand!

Answer 8

Good luck!

Answer 9

So, wait, would it be 1,4,5,7,8,9,10 etc?

Answer 10

@wio

Answer 11

Not quite, let me show.

Answer 12

\[
\overline{Q}= U-Q= \{1,2,\cancel3,4,5,\cancel6,7,8,\cancel9,10\} - \{\cancel3,\cancel6,\cancel9\} = \{1,2,4,5,10\}
\]

Answer 13

Ahh, okay. Thank you @wio I have one more question for you

Answer 14

Sure.

Answer 15

Suppose U = {1,2,3,4,5,6,7,8} and A = {1,3,5,7} and B = {4,5,6}
A subset B
True or False?
B subset U
True or False?
@wio

Answer 16

Well, if A is a subset of B, then \(A-B=\emptyset=\{\}\)

Answer 17

So you can use set different to tell.

Answer 18

I'm confused.

Answer 19

@wio

Answer 20

Do you know what a subset is?

Answer 21

To be honest, no.

Answer 22

That is the problem, you need to understand it.
If A is a subset of B, for example, that means that every element in A is also in B

Answer 23

Oh, okay, so then A subset B is false

Answer 24

@wio

Answer 25

Yeah, it is false.

Answer 26

But, B subset U isn't because {4,5,6} are all in {1,2,3,4,5,6,7} @wio

Answer 27

Correct?

Answer 28

B is a subset of U

Answer 29

Thank you!