21. Estimate the order of magnitude of the number of ping pong (table tennis) balls that would fit into your tutorial venue

without being crushed. Clearly explain your assumptions and explain each step of your reasoning.

22. Suppose that someone offers to give you 1 billion dollars if you can finish counting it out using only one-dollar bills. Estimate

the order of magnitude in years that it will take you to finish counting? Assume that you can count one bill every second, and

be sure to note that you need about 8 hours a day for sleeping and eating. Clearly explain your assumptions and explain each

step of your reasoning.