Question: 1. How many anagrams are there (including those that aren't dictionary words) of TELEPHONE?
2. Suppose that N and M are sets in the universe U. Express |N¯ ∪ M¯| in terms of the cardinalities of N,U,M and combinations of these sets. (Did you use symbols or did you use pictures in your expression?)
3. How many ways are there to arrange 15 bluejays and 3 white cats to sit in a line? What if the white cats may not sit next to each other?