5. Find the power set of each of these sets, where a and b are distinct elements. a. {a}

Suppose A is a set for which |A| = 12. How many 5-element subsets of A are there? (the number of subset of A with 5 elements)

The table shows some trees that are in two city parks. Let U be the smallest possible set that includes all the trees listed, R be the set of trees in Riverside Park, and S be the set of trees in Sleepy Hollow Park. Find R'. Sleepy Hollow Park Aspen, a Riverside Park Cherry, c Hickory, h Birch, b Aspen, a Elm, e Pine, p Cherry, c Oak, o Hickory, h Use the lowercase letters in the table to list the elements in R'. R' = O (Use a comma to separate answers as needed.)

Consider the following three sets of natural numbers less than or equal to 20: A={4, 5, 8, 11, 12, 13, 17, 18, 19, 20}  B={1, 2, 3, 5, 10, 11, 16, 20}  C={1, 3, 4, 7, 8, 12, 17, 18, 19}  Find the following:  A∪B  A∩B A∩C  B∩C A∩B∩C  A−B  B−A  AC  |A|  (A∪B∪C)C