The symmetric difference of A and B, denoted by A B, is the set containing those elements in

either A or B, but not in both A and B.

a) Find the symmetric difference o f { 1, 3 , 5 } and { 1, 2, 3 } .

b) Determine whether the symmetric difference is associative; that is, if A, B, and C are sets, does it follow that

A (B C) = (A B) C?