CREATE TABLE "singles" (
  "player" text,
  "result" text,
  "appeared" real,
  "rr_w_l" text,
  "rr_w_rate" real
);

Question: If the RR Rate is less than 0.75 with a result of RR:08,09, what is the average appeared?
SQL: SELECT AVG("appeared") FROM "singles" WHERE "rr_w_rate"<0.75 AND "result"='rr:08,09';

Question: What's the total appeared that has an RR Rate less than 0.17?
SQL: SELECT SUM("appeared") FROM "singles" WHERE "rr_w_rate"<0.17;

Question: For Angelique Kerber who had an RR Rate of less than 0.33, what's the appeared?
SQL: SELECT SUM("appeared") FROM "singles" WHERE "rr_w_rate"<0.33 AND "player"='angelique kerber';