You have a $20 bill, and you need to double it. You have 1 month, you must keep it in cash (No banks, cashapp, credit cards), you don’t have an address, a phone number, or and you can’t interact to people in public. using just the internet and an email, how do you double the money?
20+40*1-20. The first 20 you had already.
Except you’re not gonna sell any because I’m going to sell 42 tickets to a $21 prize. You’ll just be left with your $20 prize, $20 dollars, and 40 free tickets.