I'm studying for my finals and I came across these questions:
Determine the value of the following expressions:
a) $|\{a,b,c,d,e\}\cap \{c,d,e,f,g\}|=$
b) $|\{(a,b,c,d,e\}\cap\{c,d,e,f,g\})\cup\{l,c,e,g,i\}|=$
c) $|\{\ldots,-3,-2,-1,0,1,2,3\} \cap \{-1,0,1,2,3,4,\ldots\}|=$
Is it correct to say that these are the answers for the following:
a) 3 (c,d,e)
b) 7 (d,e,c,l,i,e,g)
c) 5 (-1,0,1,2,3)
because this | | notation means the number of elements..
Thanks in advance!!