How many failed the exam?
select count ( * ) from student_tests_taken where test_result = 'Fail'
And what about passed?
select count ( * ) from student_tests_taken where test_result = 'Pass'
Can you list each test result and it's count in descending order based on count?
select test_result, count ( * ) from student_tests_taken group by test_result order by count ( * ) desc
Yes, what are ids of all passed exams?
select registration_id from student_tests_taken where test_result = 'Pass'