From Church Av line 5 subway to Grand Central then train to Mt Vernon East. 1 h 18 min $13. From Church Av line 2 subway to Nereid Av. 1 h 27 min $2. From Brooklyn taxi to Mount Vernon. 33 min $134. From Brooklyn drive to Mount Vernon. 33 min $2.
There is no direct connection from Brooklyn to Mount Vernon. However, you can take the line 5 subway to Grand Central then take the train to Mt Vernon East. Alternatively, New York City Transit (MTA) operates a vehicle from Brooklyn to Mount Vernon every 5 minutes. Tickets cost $3 and the journey takes 1 h 27 min.