This one is interesting

[vettecat]

I'm sure it's a trick, but... anyone have any idea how this works? I've tried several different combinations and it keeps giving the right answer. Hm.

Comments

[points.livejournal.com]

If you take a piece of paper and just quickly do the math, you'll see that there's actually only a small subset of numbers you can generate by taking a two digit number, and subtracting the digits that make up the number. The flash picks a single 'gift' and then seeds only those subset of numbers with that gift, randomly fills in the rest. Then, it simply tells you the 'gift' it seeded in the right positions. All the rest of it is 'complexity' to hide the real trick. :)

[vettecat.livejournal.com]

I can understand that there may be only, say, 12 "live" numbers on the chart. But it did keep bringing up the right choice, and each time I used a different number. That's what's throwing me. You think it was just luck?

[points.livejournal.com]

No, not luck at all... just math and some sleight of hand. If you look at the 'gift list,' you'll see that gifts are repeated multiple times in the array. So, let's look at a subset of the answers we can generate:

10 - 1 - 0 = 9 20 - 2 - 0 = 18 ... 90 - 9 - 0 = 81
11 - 1 - 1 = 9 21 - 2 - 1 = 18 ... 91 - 9 - 1 = 81
12 - 1 - 2 = 9 22 - 2 - 2 = 18 ... ...
13 - 1 - 3 = 9 ... ... ...
... ... ... ...
19 - 1 - 9 = 9 29 - 2 - 9 = 18 ... 99 - 9 - 9 = 81

so, the -only- numbers we can possibly generate using their algorithm is:
9, 18, 27, 36, 45, 54, 63, 78, 81 And that is -it-.

To distract you, they put in all the numbers from 1 to 99 on their table... but if you look closely, the -same gift- will be listed for the nine numbers I have you above. So there's no luck involved.

Make sense, now? :)

[vettecat.livejournal.com]

It does make sense, except I got a different gift each time... oh, wait. I just hit reload a few times, and the distribution changed so a different identical gift was in those slots. Clever.

[vettecat.livejournal.com]

P.S. I think you meant "63, 72, 81..."?

[points.livejournal.com]

Most likely. I was just doing it quickly in my head while typing. ;)

[vettecat.livejournal.com]

Excuses, excuses...!

[maedbh7.livejournal.com]

Amusingly, each time I pick the number 10, it gets it wrong. -H...

[vettecat.livejournal.com]

Did you get 10 by using their formula, though?