1. The document contains solutions to chapter 19 homework problems about the quantity theory of money and theories of the demand for money. It calculates velocity of money, effects of changes in the money supply and velocity on nominal GDP, and analyzes how interest rates, transactions costs, and expectations affect the speculative demand for money according to theories by Keynes, Friedman, Baumol, and Tobin. 2. It finds that banning credit cards would reduce velocity as people hold more money for transactions. If money supply increases by 300% while velocity and output stay constant, price level must also rise by 300% to restore full employment. Tobin argued people hold both money and bonds due to risk preferences.