This a discrete Math question. ?

Question

Let U = {q, r, s, t, u, v, w, x, y, z}, A = {q, s, u, w, y}, B = {q, s, y, z}, C = {v, w, x, y, z}. List the elements in the set A U (B upside down U C)

{q, y, z}

{q, r, w, y, z}

{q, s, u, w, y, z}

{q, w, y}

I think the 3rd answer is the correct one. Can anyone tell me if I am on the correct track?

Answer 1

A ∪(B ∩ C) = {q, s, u, w, y, z}

Start with (B ∩ C).  What is in both B and C?  Only y and z are in both B and C.  So, (B ∩ C) = {y, z}.  Now add all the elements of (B ∩ C) to all the elements of A.  That gives you {q, s, u, w, y, z}, so yes, you are correct.