Which B Score has a Total larger than 15.325, and an A Score smaller than 6.4?
CREATE TABLE "qualified_competitors" (
  "position" real,
  "gymnast" text,
  "a_score" real,
  "b_score" real,
  "total" real
);
SELECT SUM("b_score") FROM "qualified_competitors" WHERE "total">15.325 AND "a_score"<6.4;