CREATE TABLE table_name_22 (grid INT, laps VARCHAR, rider VARCHAR)

Which Grid has Laps of 24, and a Rider of marco melandri?
SELECT SUM(grid) FROM table_name_22 WHERE laps = 24 AND rider = "marco melandri"
SELECT SUM("grid") FROM "table_name_22" WHERE "laps" = 24 AND "marco melandri" = "rider"