Graded homework 2

#### Grade: 5/5

Excellent work, Jenny! You have an excellent grasp of logic for each of these functions.
I made a few inline comments that you should checkout.

Once you've read these comments, make a comment to the pull request or send me/Diana an email, letting us know that you've checked them out. Afterwards, close the PR (and optionally delete the graded branch)

#### REMEMBER NOT TO MERGE THESE PRs!