Show records (name and id) of stations installed in December.
select name, id from station where installation_date like "12/%"
Which had more than 14 bikes available?
select t1.name, t1.id from station as t1 join status as t2 on t1.id = t2.station_id group by t2.station_id having avg(t2.bikes_available) > 14
Union those two.
select t1.name, t1.id from station as t1 join status as t2 on t1.id = t2.station_id group by t2.station_id having avg(t2.bikes_available) > 14 union select name, id from station where installation_date like "12/%"