SELECT grade ,  count(DISTINCT classroom) ,  count(*) FROM list GROUP BY grade
For each grade, report the grade, the number of classrooms in which it is taught and the total number of students in the grade.
SELECT grade , count ( DISTINCT classroom ) , count ( * ) FROM list GROUP BY grade
select grade , count ( distinct classroom ) , count ( * ) from list group by grade
For each grade , report the grade , the number of classrooms in which it is taught and the total number of students in the grade .