Question

The symmetric difference of A = {1, 2, 3} and B = {3, 4, 5} is
(a) {1, 2}
(b) {1, 2, 4, 5}
(c) {4, 3}
(d) {2, 5, 1, 4, 3}

Answer 1

(b) {1, 2, 4, 5}
Here,
A = {1, 2, 3} and B = {3, 4, 5}
The symmetric difference of A and B is given by :-
$(A-B)\cup (B-A)$
Now, we have:
$$\begin{gathered} (A-B)=\{1,2\} \\ (B-A)=\{4,5\} \\ (A-B)\cup (B-A)=\{1,2,4,5\} \end{gathered}$$