# Thread: Set language and Notation questions

1. ## Set language and Notation questions

Hi guys, why is my answer (7) wrong? Please do explain, thank you very much!

2. ## Re: Set language and Notation questions

Originally Posted by FailInMaths
Attachment 22232
Hi guys, why is my answer (7) wrong? Please do explain, thank you very much!
$\displaystyle 0\le n(A\cap B)\le\min\{n(A),n(B)\}~.$

3. ## Re: Set language and Notation questions

hi

if you read the first line in the pic you will see that it says:"Your answer for Blank 1 '12' is incorrect"

4. ## Re: Set language and Notation questions

Originally Posted by anonimnystefy
hi

if you read the first line in the pic you will see that it says:"Your answer for Blank 1 '12' is incorrect"
Well $\displaystyle \min\{n(A),n(B)\}=7$

5. ## Re: Set language and Notation questions

Originally Posted by anonimnystefy
hi

if you read the first line in the pic you will see that it says:"Your answer for Blank 1 '12' is incorrect"
I know what you mean but somehow that bold number is the answer

6. ## Re: Set language and Notation questions

Originally Posted by plato
well $\displaystyle \min\{n(a),n(b)\}=7$
edit : -

7. ## Re: Set language and Notation questions

I have a question for you.
What does $\displaystyle n(\varepsilon)$ mean?
In forty years, I have never seen that symbol.

Yes, 7 is the correct answer.
Because $\displaystyle A\cap B\subseteq B$ that forces $\displaystyle n(A\cap B)\le n(B)$.

8. ## Re: Set language and Notation questions

hi Plato

i think it represents number of elements in the universal set.

9. ## Re: Set language and Notation questions

Originally Posted by Plato
I have a question for you.
What does $\displaystyle n(\varepsilon)$ mean?
In forty years, I have never seen that symbol.
Universal set, so is my answer right or wrong? I just don't get it!!!!

Edit: ok.. it's good to hear that my answer was correct, had been thinking for a long while before approaching to this forum. I thought that I could never doubt the system.