What is the total of NA for set 4, a score of 3-0 and a 26-24 for set 2?
CREATE TABLE "results_pool_c" (
  "date" text,
  "score" text,
  "set_1" text,
  "set_2" text,
  "set_3" text,
  "set_4" text,
  "set_5" text,
  "total" text
);
SELECT "total" FROM "results_pool_c" WHERE "set_4"='na' AND "score"='3-0' AND "set_2"='26-24';