17. If A= 1,3,5,7,9 and B= 2,4,6,8 what is the intersection of set A and B? __ 18. Acap B= 19. Acup B= 20. A^C= __ 21. B^C= __

17. The intersection of set A and B is the set of elements that are common to both A and B. In this case, there are no common elements between set A and B. Therefore, the intersection of set A and B is an empty set, denoted as $\emptyset$.<br /><br />18. $A\cap B=\emptyset$<br /><br />19. The union of set A and B is the set of all elements that are in A, B, or both. In this case, the union of set A and B includes all the elements from both sets. Therefore, the union of set A and B is $\{1,2,3,4,5,6,7,8,9\}$.<br /><br />20. The complement of set A, denoted as $A^{C}$, is the set of all elements that are not in A. In this case, since A contains the elements $\{1,3,5,7,9\}$, the complement of A includes all the elements that are not in A. Therefore, $A^{C}=\{2,4,6,8\}$.<br /><br />21. The complement of set B, denoted as $B^{C}$, is the set of all elements that are not in B. In this case, since B contains the elements $\{2,4,6,8\}$, the complement of B includes all the elements that are not in B. Therefore, $B^{C}=\{1,3,5,7,9\}$.