CREATE TABLE table_72225 ("Member" TEXT, "Week Arrived On Main Island" TEXT, "Week Sent To Third Island" TEXT, "Original Tribe" TEXT, "Tribe They Chose To Win" TEXT)

What week was the member who arrived on the main island in week 6 sent to the third island?
SELECT "Week Sent To Third Island" FROM table_72225 WHERE "Week Arrived On Main Island" = '6'
SELECT "Week Sent To Third Island" FROM "table_72225" WHERE "Week Arrived On Main Island" = '6'