To solve this problem, we should remember that the formula
for reserve ratio is:
r = reserves / demand deposits
Where,
r = reserve ratio
reserves = $ 3 billion in government securities
Therefore the demand deposits is:
demand deposits = $ 3 billion / 0.25
demand deposits = $ 12 billion
Since $ 3 billion was bought, therefore the increase in the
lending ability of the commercial banks is:
$ 12 - $ 3 billion = $ 9 billion
Answer:
$ 9 billion