Question

This is so confusing :(
Given U = {10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20}, A = {12, 14, 16, 18, 20}, and B = {11, 13, 14, 15, 18, 19, 20}.

Find A′ ∩ B′. Do not skip to the answer. Show your work, finding A’, then B’ then find their intersection.

Answer 1

A' is the same as U-A, i.e. all the elements of A' must be in U but NOT in A.
So A'={10,11,13,15,...}
and
B'={10,12,...}
A'∩B' contains elements that are members of both A' and B', or
A'∩B' = {10,...}