Question 1191833
<pre>
A ∩ B'

Substitute {q, s, u, w, y} for A and {q, s, y, z} for B:

{q, s, u, w, y} ∩ {q, s, y, z}'

Take care of the " ' " first.  That means "complement", which means
to take all the elements of U that are not members of {q, s, y, z}.
So in place of {q, s, y, z}' we write {r, t, u, v, w, x}.

{q, s, u, w, y} ∩ {r, t, u, v, w, x}

Now " ∩ " (intersection) says to take ONLY the elements which are
IN COMMON to both sets.  That is, only those elements which are 
contained in both sets on the left and right of ∩.  There are only 
two:

{u, w}     <--answer

Edwin</pre>