CREATE TABLE "250cc_classification" (
  "rider" text,
  "manufacturer" text,
  "laps" real,
  "time" text,
  "grid" real
);

Question: What is the lowest grid number for Yamaha?
SQL: SELECT MIN("grid") FROM "250cc_classification" WHERE "manufacturer"='yamaha';

Question: How many laps had a grid over 16 and a Time of +1:35.890?
SQL: SELECT "laps" FROM "250cc_classification" WHERE "grid">16 AND "time"='+1:35.890';

Question: What was the lowest lab for Gilera with a grid less than 12?
SQL: SELECT MIN("laps") FROM "250cc_classification" WHERE "manufacturer"='gilera' AND "grid"<12;

Question: What is the highest Grid with a time of +1:19.905, and less than 20 laps?
SQL: SELECT MAX("grid") FROM "250cc_classification" WHERE "time"='+1:19.905' AND "laps"<20;

Question: What Rider has a Grid of 21?
SQL: SELECT "rider" FROM "250cc_classification" WHERE "grid"=21;