CREATE TABLE "classification" (
  "driver" text,
  "constructor" text,
  "laps" real,
  "time_retired" text,
  "grid" real
);

Question: How many laps are associated with a time of + 1:39.591?
SQL: SELECT "laps" FROM "classification" WHERE "time_retired"='+ 1:39.591';

Question: What is the average number of laps for a grid of 6?
SQL: SELECT AVG("laps") FROM "classification" WHERE "grid"=6;