CREATE TABLE "races" (
  "round" real,
  "name" text,
  "circuit" text,
  "date" text,
  "winning_driver" text,
  "winning_car" text
);

Question: What circuit had an ensign n180 as the winning car in round 5?
SQL: SELECT "circuit" FROM "races" WHERE "winning_car"='ensign n180' AND "round"=5;

Question: How many rounds total were there on may 31?
SQL: SELECT COUNT("round") FROM "races" WHERE "date"='may 31';

Question: What was the average round for the oulton park circuit?
SQL: SELECT AVG("round") FROM "races" WHERE "circuit"='oulton park';