Answer and Explanation:
a. In case when the new bills are kept by the people so the supply of money would be increase by a very similar amount as it was dropped off the plane. That's because the banking is not in the image, so there is no impact on the money multiplier.
b. If the amount is deposited in the bank, the cash supply would rise with the money multiplier being taken into account. Money Multiplier = Deposited currency / reserve ratio. The overall supply of money that will raise be 1 billion / 0.1.
c.Again, if a 100% reserve banking is exercised by the bank, so the boosted money supply would be the same value as it has been deposited.
d. If half of the value is held by the public and half of the value is deposited with the bank at 10% of the reserves, the supply of money rises by half of the amount which is held by the public in addition of half of the value / reserve ratio that is 10%.