there are only nine possible answers to the first question. 81, 72, 63, 54, 45, 36, 27, 18 and 9.
If you look at the page with the gifts on, the same gift will be against all of the above numbers, so no matter what combination of numbers, the answer will ultimately be the same. The actual gift changes each time you reload the page, which is what makes you think it's guessin correctly