7.5, due on 3/18

1.  The proofs were pretty easy but I didn't realize before the difference between Z4 and Z2xZ2  and between Z6 and S3 but now it's very clear.

2.  This section was pretty straightforward.  The theorems seem very useful.  If you know the order of a group you can tell a lot about it if the order is prime, 4, or 6.