Question

Given: A = {a, e, i, o, u}, B = {a, l, g, e, b, r}, C = {m, y, t, h}, A ∩ C is

m, a, e, i, o, u, t, h
the empty set
i
a, e, i, o, u, y

Answer 1

What do the two sets, A and C, have in common?

Answer 2

A n C is the set containing the elements that A and C share.
If they do not have anything in common, we say the empty set is equal to
A n C.