3000. When the first clue was solved BT  donated £30,000 (41:18 left on clock); the second clue netted a  further £40,000 (30:52 left); the third £50,000 (20:14 remaining);  the fourth £60,000 (10:33); and the fifth and final clue £70,000  (with 01:14 to spare!) The total BT donation to the telethon appeal  was £250,000.