CREATE TABLE table_17578 ("Season" TEXT, "Mens singles" TEXT, "Womens singles" TEXT, "Mens doubles" TEXT, "Womens doubles" TEXT, "Mixed doubles" TEXT)

How many mens doubles took place in 1970/1971?
SELECT COUNT("Mens doubles") FROM table_17578 WHERE "Season" = '1970/1971'
SELECT COUNT("Mens doubles") FROM "table_17578" WHERE "Season" = '1970/1971'