CREATE TABLE table_10408617_5 (prefixes VARCHAR2, scheme VARCHAR2, approx_premium VARCHAR2)

What prefixes are priced at pence per minute, fixed at all times with a premium of 3p/min?
SELECT prefixes FROM table_10408617_5 WHERE scheme = "Pence per minute, fixed at all times" AND approx_premium = "3p/min"
SELECT "prefixes" FROM "table_10408617_5" WHERE "3p/min" = "approx_premium" AND "Pence per minute, fixed at all times" = "scheme"