Find the number of students whose city code is NYC, please?
SELECT count ( * )  FROM STUDENT AS T1 JOIN VOTING_RECORD AS T2 ON T1.StuID   =   Class_Senator_Vote WHERE T1.city_code   =   "NYC"
number of students with city code NYC = COUNT(*) WHERE city_code = 'NYC'; joining the STUDENT table with VOTING_RECORD table on StuID = Class_Senator_Vote;