Monetaria (a made up country), once a barter economy, establishes its central bank. The central bank prints 500,000 of $1 bills, and puts them into circulation.

a. If people hold all money as currency, what is the quantity of money?
b. If people hold all money as demand deposits, and banks maintain 100% reserves, what is the quantity of money?
c. If people hold all money as demand deposits and banks maintain a reserve ratio of 20%, what is the quantity of money?