CREATE TABLE "complete_world_championship_results" (
  "year" real,
  "entrant" text,
  "chassis" text,
  "engine" text,
  "points" real
);

Question: What was the earliest year for a car with 3 points and Cooper t20 chassis?
SQL: SELECT MIN("year") FROM "complete_world_championship_results" WHERE "points"=3 AND "chassis"='cooper t20';