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}
Determine the following:
A.{s,u,w}
B.{t,v,x}
C.{r,t,v,x}