In a science-fiction story my friend is writing, a group of aliens have come to take over the planet.   They are kindly aliens, however, and don't want to kill us all.   They only want all the people in the world to be together somewhere where they can transform us all into Borg penguins.   They plan to create tall 100 story apartment buildings to keep us in while they are preparing the transformation process.   Every family would get a small, but comfortable apartment. Could they fit them all on the College Park campus? In the state of Maryland? Estimate how much space they would need for all of these buildings and compare it to some area you know.  
Be sure to clearly state your assumptions and how you came to the numbers you estimated,
since grading on this problem will be mostly based on your reasoning, not on your answer.