Problem of the Week
for Friday, December 2

You remember how you and your sister both drink a lot of milk, right?
Well, now you have a friend sleeping over, and your dad has once again brought home
a full (transparent plastic) container. This time, your sister promises to use exactly one-third
of the milk and leave you and your friend the rest. When you get up, you look in the fridge and take
out the container. You can see the milk level, and she has left you a felt-tip marker and a large empty pitcher.
How can you tell if she was fair, generous or greedy?