What is the lowest played when draws P.K. Wins / P.K. Losses is 3/0, and points is larger than 18?
CREATE TABLE "torneo_apertura" (
  "position" real,
  "team" text,
  "played" real,
  "wins" real,
  "draws_p_k_wins_p_k_losses" text,
  "losses" real,
  "scored" real,
  "conceded" real,
  "points" real
);
SELECT MIN("played") FROM "torneo_apertura" WHERE "draws_p_k_wins_p_k_losses"='3/0' AND "points">18;