Let S be the universal set, where: S = { 1 , 2 , 3 , ... , 18 , 19 , 20 } Let sets A and B be subsets of S , where: Set A = { 2 , 5 , 9 , 11 , 12 , 14 , 15 , 17 , 18 } Set B = { 4 , 7 , 8 , 9 , 10 , 12 , 15 , 17 , 18 , 19 , 20 } Find the following: LIST the elements in the set ( A ∪ B ): ( A ∪ B ) = { } Enter the elements as a list, separated by commas. If the result is the empty set, enter DNE LIST the elements in the set ( A ∩ B ): ( A ∩ B ) = { } Enter the elements as a list, separated by commas. If the result is the empty set, enter DNE