chp 24 order of exercises

[hardin47]

I changed the order of exercises so that a student could work through all the parts with a single dataset for evens or for odds.

Here is the original ordering:

Here is the ordering I changed it to:

[hardin47]

chapter 21 is all over the place. should i reorder?

[mine-cetinkaya-rundel]

sure i think esp for the later chapters this is totally fine and now is a good time to clean up

[hardin47]

fixed