CREATE TABLE table_203_808 (id NUMBER, "rank" NUMBER, "peak name" CLOB, "elevation" CLOB, "location" CLOB, "notes" CLOB)

how many feet separate the 7th and 8th ranked highest peaks ?
SELECT (SELECT "elevation" FROM table_203_808 WHERE "rank" = 7) - (SELECT "elevation" FROM table_203_808 WHERE "rank" = 8)
SELECT (SELECT "elevation" FROM "table_203_808" WHERE "rank" = 7) - (SELECT "elevation" FROM "table_203_808" WHERE "rank" = 8)