The government of Eastlandia uses measures of monetary aggregates similar to those used by the United States and the central bank of Eastlandia imposes a required reserve ratio of 10%. Given the following information, answer the questions below.

Bank deposits at the central bank (Eastlandia's Fed) = $200 million

Currency held by the public = $150 million

Currency in bank vaults = $100 million

Checkable bank deposits = $500 million

Travelers' checks = $10 million

a. M1 is $ __________ million.

b. The commercial banks are holding excess reserves of $ __________ million.

c. The commercial banks can potentially increase the money supply by $ __________ million.