# Set language and Notation questions

• Sep 10th 2011, 11:37 AM
FailInMaths
Set language and Notation questions
http://i1099.photobucket.com/albums/...elephant/Z.jpg
Hi guys, why is my answer (7) wrong? Please do explain, thank you very much!
• Sep 10th 2011, 11:45 AM
Plato
Re: Set language and Notation questions
Quote:

Originally Posted by FailInMaths
Attachment 22232
Hi guys, why is my answer (7) wrong? Please do explain, thank you very much!

$0\le n(A\cap B)\le\min\{n(A),n(B)\}~.$
• Sep 10th 2011, 11:46 AM
anonimnystefy
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"
• Sep 10th 2011, 11:49 AM
Plato
Re: Set language and Notation questions
Quote:

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 $\min\{n(A),n(B)\}=7$
• Sep 10th 2011, 11:52 AM
FailInMaths
Re: Set language and Notation questions
Quote:

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
• Sep 10th 2011, 11:53 AM
FailInMaths
Re: Set language and Notation questions
Quote:

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

edit : -
• Sep 10th 2011, 11:57 AM
Plato
Re: Set language and Notation questions
I have a question for you.
What does $n(\varepsilon)$ mean?
In forty years, I have never seen that symbol.

Yes, 7 is the correct answer.
Because $A\cap B\subseteq B$ that forces $n(A\cap B)\le n(B)$.
• Sep 10th 2011, 11:59 AM
anonimnystefy
Re: Set language and Notation questions
hi Plato

i think it represents number of elements in the universal set.
• Sep 10th 2011, 12:00 PM
FailInMaths
Re: Set language and Notation questions
Quote:

Originally Posted by Plato
I have a question for you.
What does $n(\varepsilon)$ 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. (Angry)
• Sep 10th 2011, 12:01 PM
Plato
Re: Set language and Notation questions