What were the Oct. temperatures for the city that had Nov. temperatures of 51/30?
CREATE TABLE "temperature" (
  "city" text,
  "jan" text,
  "feb" text,
  "mar" text,
  "apr" text,
  "may" text,
  "jun" text,
  "jul" text,
  "aug" text,
  "sep" text,
  "oct" text,
  "nov" text,
  "dec" text
);
SELECT "oct" FROM "temperature" WHERE "nov"='51/30';