Question: How old were Mitchell & Jessica when they danced the Cha-cha-cha?
SQL: SELECT "Ages" FROM "2-17862135-20" WHERE "Dance" = 'Cha-cha-cha' AND "Pair" = 'Mitchell & Jessica';

Question: Who danced the Cha-cha-cha on November 18, 2008?
SQL: SELECT "Pair" FROM "2-17862135-20" WHERE "Dance" = 'Cha-cha-cha' AND "Date" = 'November 18, 2008';

Question: Who danced the Samba on October 14, 2008?
SQL: SELECT "Pair" FROM "2-17862135-20" WHERE "Date" = 'October 14, 2008' AND "Dance" = 'Samba';