CREATE TABLE table_3634 ("No. in series" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original U.S. air date" TEXT, "Prod. code" FLOAT)

How many episodes have the title 'revenge of the mummy'?
SELECT COUNT("Original U.S. air date") FROM table_3634 WHERE "Title" = 'Revenge of the Mummy'
SELECT COUNT("Original U.S. air date") FROM "table_3634" WHERE "Title" = 'Revenge of the Mummy'