CREATE TABLE "series_2" (
  "num" real,
  "airdate" text,
  "no_of_couples" real,
  "1st_couple" text,
  "2nd_couple" text,
  "3rd_couple" text,
  "4th_couple" text,
  "viewers_millions" text,
  "itv1_weekly_ranking" text
);

Question: How many episode numbers are there on the show whose first couple was Stuart and Pegah>?
SQL: SELECT COUNT("num") FROM "series_2" WHERE "1st_couple"='Stuart and Pegah';

Question: Who were the 3rd couple that were viewed by 4.89 million viewers? 
SQL: SELECT "3rd_couple" FROM "series_2" WHERE "viewers_millions"='4.89';