what is the total number of tackles when fumr is 0, totaltk is 54 and yards is less than 0?
CREATE TABLE "defense" (
  "player" text,
  "tackles" real,
  "asst" real,
  "total_tk" real,
  "sack" real,
  "yards" real,
  "fum_r" real
);
SELECT COUNT("tackles") FROM "defense" WHERE "fum_r"=0 AND "total_tk"=54 AND "yards"<0;