Table: train_schedule_9
Columns: train_no
train_name
arrival
departure
days
platform_no

Question: How many trains depart at 17:30?
SQL: SELECT COUNT("train_no") FROM train_schedule_9 WHERE "departure" = '17:30'

Question: How many trains arrive at 11:00?
SQL: SELECT COUNT("train_no") FROM train_schedule_9 WHERE "arrival" = '11:00'