In reply to:

...(incidentally, i sent my guess at 5:57am on Tuesday... what time does this Tracy person wake up, for pete's sake??)

bridget96,

Perhaps she spotted what the words had in common on Day 1, with only the word "dekko" to go by?

If that's the case, she'd no doubt excel at this maths puzzle, which has only one correct answer, of course...

Q. Provide the next four numbers in the following series:

3 , _ , _ , _ , _