CREATE TABLE table_13660 ("Year" TEXT, "Start" TEXT, "Qual" TEXT, "Rank" TEXT, "Finish" TEXT, "Laps" FLOAT)

Which Laps have a Finish of 15?
SELECT "Laps" FROM table_13660 WHERE "Finish" = '15'
SELECT "Laps" FROM "table_13660" WHERE "Finish" = '15'