I don’t understand this problem and need help.

Question

Have you ever thought about the size of the U.S. national debt? Have you pondered the literal size or weight of it? How large is the U.S. national debt right now, and more important, how do you make sense of a number that large?

How high would the debt stack if it were represented with $1 bills? What if it were represented with the largest denomination in circulation today? How much area would the debt cover if it were represented with a single layer of $1 bills? Could you carpet the United States with its own debt? How much would the debt weigh if it were represented with $1 bills? What if it were represented with quarters?

Put each of your answers into perspective by comparing the answer to some common object. For example, you might consider the distance to the moon or the weight of the Titanic.

How long would it take the country to pay off the national debt if everyone contributed at a certain rate? How does our national debt compare to the economy of another country? Use some international comparison to put it into perspective.

To understand the true size of the national debt, there are numerous factors to consider. How else could we investigate this situation? In other words... What Else can we do?