# Thread: [SOLVED] what does &quot;n&quot; mean?

1. ## [SOLVED] what does &quot;n&quot; mean?

For instance, if A = (a,c,d,e) and B= (a,b) and C= (b,c,e,f), then what is n((A -B) - C)? And n(A ∩ B ∩ C)? What is this n?? Thanks for any help

2. Originally Posted by Allan89a
For instance, if A = (a,c,d,e) and B= (a,b) and C= (b,c,e,f), then what is n((A -B) - C)? And n(A ∩ B ∩ C)? What is this n?? Thanks for any help
nA usually denotes the No of elements in the set,for example nA in the above problem is 4
And n( $A\cap B\cap C$) = 0

3. Yeah, I figured it out later on, but thanks!