What is the staff ID of the staff with the first name Christop?
select staff_id from staff where staff_first_name = "Christop"
How many problems have been reported under staff ID 10?
select count ( * ) from problems as t1 join staff as t2 on t1.reported_by_staff_id = t2.staff_id where t2.staff_id = "10"
Can you give me a list of the problem descriptions he reported?
select t1.problem_description from problems as t1 join staff as t2 on t1.reported_by_staff_id = t2.staff_id where t2.staff_first_name = "Christop"