The economy of Yorkland contains 4,000 $1 bills

1. If people hold all money as currency, what is the quantity of money (money supply)?
2. If people hold all money as demand deposits and banks maintain 100 percent reserves, what is the quantity of money?
3. If people hold equal amounts of currency and demand deposits and banks maintain 100 percent reserves, what is the quantity of money?
4. If people hold all money as demand deposits and banks maintain a reserve ratio of 20 percent, what is the quantity of money?
5. If people hold equal amounts of currency and demand deposits and banks maintain a reserve ratio of 20 percent, what is the quantity of money?