Question

Let U=(1,2,3,4,5,6,7,8,9,10) Let A = {2,4,6,8,10}. Let B=(1,3,4,6,9} Determine (A - B)'.​

Answer 1

A - B is the complement of B in A; in other words, all the elements of A that do not belong to B.

Since A ∩ B = {4, 6}, we have

A - B = {2, 8, 10}

Then the complement of A - B, denoted (A - B)' is all the elements of the universal set U that do not belong to A - B.

(A - B)' = {1, 3, 4, 5, 6, 7, 9}