Question

Perform the given set operations. (Enter solutions from smallest to largest. If there are any unused answer boxes, enter NONE in the last boxes.)
U = {10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20}

(a) {13, 14, 20}
(b) {13, 14, 15, 17, 20}
(c) {12, 15, 16, 18,19}
(d) {11, 14, 17, 19, 20}