Assume that the reserve requirement ratio equals 15%, banks hold only the amount they are legally required to hold in reserves, and households are happy with their cash balances. Calculate the change in the money supply that we would expect would result from a Fed purchase of $10 billion of treasuries in the secondary market. $15.00 billion increase $15.00 billion decrease $66.67 billion increase $66.67 billion decrease $150.00 billion increase