How many fast laps are in 6 races with 30 points in the World Series by Nissan?
CREATE TABLE "career_results" (
  "season" text,
  "series" text,
  "team" text,
  "races" text,
  "wins" text,
  "fast_laps" text,
  "points" text,
  "pos" text
);
SELECT "fast_laps" FROM "career_results" WHERE "series"='world series by nissan' AND "races"='6' AND "points"='30';