Tonight's HW

So as you may have noticed on the website there was a slight change in the homework.  Instead of doing all the evens, I want you to add in #19 and #21.  So you are doing 18-22all, don't just do the evens.  The reason is #19 and #21 deal with the difference between Combinations and Permutations so I want you to see all, not just the evens.