Which one of the following gives the members of the set A1 n B n C?
A.
Φ
B.
{s}
C.
{t, u}
D.
{y, z}
Correct answer is A
A1 = Elements in the universal set but not in A = {s, w, x, y, z} B = {r, s. t, u} C = {t, u, v, w, x} A1 n B n C = elements common to the three sets = none = empty set = Φ