Question

Let A = {3, 6, 12, 15, 18, 21}, B = {4, 8, 12, 16, 20}, C = {2, 4, 6, 8, 10, 12, 14, 16} and D = {5, 10, 15, 20}. Find:
(i) $A-B$
(ii) $A-C$
(iii) $A-D$
(iv) $B-A$
(v) $C-A$
(vi) $D-A$
(vii) $B-C$
(viii) $B-D$

Answer 1

Given:
A = {3, 6, 12, 15, 18, 21}, B = {4, 8, 12, 16, 20}, C = {2, 4, 6, 8, 10, 12, 14, 16} and D = {5, 10, 15, 20}
(i) $A-B$ = {3, 6, 15, 18, 21}
(ii) $A-C$ = {3, 15, 18, 21}
(iii) $A-D$ = {3, 6, 12, 18, 21}
(iv) $B-A$ = {4, 8, 16, 20}
(v) $C-A$ = {2, 4, 8, 10, 14, 16}
(vi) $D-A$ = {5, 10, 20}
(vii) $B-C$ = {20}
(viii) $B-D$ = {4, 8, 12, 16}