How was the great disinflation of the 1980s achieved? What was the "cost" of the disinflation?

What was the cause of the German hyperinflation from 1919 to 1923?

What is the current Federal Funds rate? What does that tell you about the effectiveness of future monetary policy? (Remember the Fed to counter a recession uses expansionary monetary policy that results in lower interest rates.) 10 points The current Federal Funds rate is 1.25%.