Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now: https://www.khanacademy.org/economics-finance-domain/core-finance/money-and-banking/banking-and-money/v/banking-8-reserve-ratios How reserve requirements limit how much lending a bank can do. More free lessons at: http://www.khanacademy.org/video?v=VP3nKDUw1jA