CREATE TABLE table_25792 ("Rank" FLOAT, "City/Town" TEXT, "County" TEXT, "Region/Province" TEXT, "Population" FLOAT, "Country" TEXT)

When 20 is the rank and north west is the region/province what is the county?
SELECT "County" FROM table_25792 WHERE "Region/Province" = 'North West' AND "Rank" = '20'
SELECT "County" FROM "table_25792" WHERE "Rank" = '20' AND "Region/Province" = 'North West'