CREATE TABLE table_name_21 (laps NUMBER, time_retired VARCHAR2, grid VARCHAR2)

Tell me the sum of laps with a time/retired of +13 laps with grid more than 18
SELECT SUM(laps) FROM table_name_21 WHERE time_retired = "+13 laps" AND grid > 18
SELECT SUM("laps") FROM "table_name_21" WHERE "+13 laps" = "time_retired" AND "grid" > 18