Trade Ya
 

Ever since grade school and school lunches, I have enjoyed trading items with my friends. So, here is the deal. I will give you $1,000,000 on the first of next month. All that I ask in return is for you to pay me back 1 penny the first day, 2 pennies the next day, 4 pennies the third day, 8 pennies the fourth day, and so on. After a week, for instance, you would need to pay me back only 64 cents.

Will you make the trade? It seems like a good idea!

How much would you have to pay me after two weeks?
After three weeks? After four weeks? After 31 days?

How many days would it take for you to end up paying me more than I gave you?

This doubling concept is similar to the concept of pyramid selling. A number of peope are hired to sell a product, then each sales person in turn is asked to find one more salesperson, and so on. If you could enlist a new person to sell for you each week and everyone working for you did the same, how long would it take for you to have a million people selling for you?