-- Database schema
| list : LastName [ TEXT ] primary_key , FirstName [ TEXT ] , Grade [ INT ] , Classroom [ INT ] | teachers : LastName [ TEXT ] primary_key , FirstName [ TEXT ] , Classroom [ INT ] |
-- -- 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;