Section 1
Permutations
The six permutations of $1,2,3$ are given in the discussion. Which of these permutations are even and which are odd?
The 24 permutations of $1,2,3,4$ are given in the discussion. Which of these are even and which are odd?
Show that half of the permutations on $1,2, \ldots, n$ are even, and the other half are odd.