Question

Let A={-1,1,3,5,7,9,11} B={3,6,9,12} and C={7,11,17}. Find the following.
A ∩ B

Answer 1

A n B means just find what those two sets have in common
if they do not have anything in common write A n B is the empty set

Answer 2

I dont know what they have in common?

Answer 3

so you looked at both sets and you don't see any elements that are in both sets?

Answer 4

ohh okay now i see

Answer 5

they both have 3 and 9
so A n B={3,9}