what is the birth date when the weight (kg) is 100 and the world rank is 2?
CREATE TABLE "sortable_list_of_competitors_with_s_kipp" (
  "nation" text,
  "birth_date" text,
  "height_m" text,
  "weight_kg" text,
  "world_rank" text
);
SELECT "birth_date" FROM "sortable_list_of_competitors_with_s_kipp" WHERE "weight_kg"='100' AND "world_rank"='2';