Close. I picked your prediction minus 3. Although, in retrospect, I seem to have vaguely had it in my mind that the range was 1 to 30 (didn't have your message in front of me while I was thinking about it).
Now I need to go back and edit my prediction to "B".
I want to ask a question of those who have this thing solved, please peek.
How does the test determine which card I picked? From 6 cards it goes to 5, and every time it had the right card value: king, queen, or jack, even though it changed all the remaining suits. Is that just probability?
It doesn't pick your card at all. It shows you six cards, then shows you five different cards. It then tells you that your card isn't one of the five cards. Of course it won't be since none of the first group of cards are there. Test this - do the test and pick ALL the cards - you'll notice that the test gets it 'right' even then!
It plays on the fact that face cards are all relatively similar to one another and the participant just assumes the second group of face cards represent the cards they didn't pick. If you make the test more obvious, its trick is plainer. Here are three colours, pick one of them:
Red, Green, Blue
OK, now I'm going to remove the colour you thought of:
Purple, Orange
I'm willing to bet that I managed to 'pick' your colour out of the list!
Hiding spoiler - Highlight what's in the white box to see text - Adminnemooseus
Crap, you know every game starts with both a black and a red king, queen, and jack. Apparently, when I 'investigated', the black king had been entirely removed from representation in the new five cards, and I had picked by chance a black king...so altogether I was still jokered into thinking there was more going on. Apparently if there was a black king of a different suit I would have over-looked that as a matter of course.