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

Bank deposits at the central bank = $200 million

Currency held by public = $150 million

Currency in bank vaults = $100 million

Chequable bank deposits = $500 million

a. What is M1+?

b. What is the monetary base?

c. Are the commercial banks holding excess reserves?

d. Can the commercial banks increase chequable bank deposits? If yes, by how much can chequable bank deposits increase?