When davao city is the  home or representative town or province and clash 2010 is the edition how many ages are there?
CREATE TABLE "teen_edition_housemates" (
  "name" text,
  "home_or_representative_town_or_province" text,
  "age" real,
  "edition" text,
  "total_days_in_pbb_house" real,
  "duration" text,
  "status" text
);
SELECT COUNT("age") FROM "teen_edition_housemates" WHERE "edition"='Clash 2010' AND "home_or_representative_town_or_province"='Davao City';