whats going on here?

[99ta]

http://www.regiftable.com/regiftingrobinpopup.html

 

seriously, whats the trick?

[jeffro]

hmmm trying it next without moving my mouse

[jeffro]

ok:confused:

[wnaplay1647545503]

Weird

[LJ]

Ah I tricked her!

[bahd-ler]

Got me... hmm.

[wnaplay1647545503]

The secret is in the way you are told to choose the number. Although they give you 90 numbers to choose from and then show you a table of 100 items to search through, because of the method they gave you for selection, you are really only able to land on a tiny fraction of possible selections.

 

Think about all the possible outcomes, using that method, between the numbers 10 and 20, for instance. 1 + 0 = 1. 10 - 1 = 9. When you add 1 to 10 you get 11. But then the sum of the digits is 2. So that every time you increment the total number (10, 11, 12, . . . ), you're also incrementing the number you're going to subtract (1, 2, 3, . . . ), meaning that the difference will always be the same, at least until you reach 20. Because one of the digits is now 0, the sum of the digits is much smaller than its predecessor. But this new result will hold until you reach 30, and so on.

 

So in general, unless the original number you choose ends in 0, the difference between it and the sum of its digits will be the same as that of its predecessor. The upshot of which is that there are only 9 possible outcomes, as each group of 10 numbers maps onto one possible outcome. Which, in turn means that there are only 10 possible items for the user to pick, and the program, choosing at random, has a 1 in 9 chance of getting it right, rather than 1 in 100.

 

The next part is the trick. The program produces a different set of gifts each time you run it and the reason it shows you a field of a hundred different outcomes (when in fact only 9 are possible) is to mask the fact that every possible outcome is matched with the same gift. Thus no matter what number you chose originally, you're always going to be bumped down to exactly one gift. And as long as you don't know what to look for (all multiples of nine point to the same gift), you probably wouldn't notice that it would be literally impossible to follow the rules and end up with a gift other than the one chosen for you in advance.

Maybe?

[RedRocket1647545505]

You always get a multiple of 9, you morons. 9,18,27,36,etc.....are all the same.

[LJ]

You always get a multiple of 9, you morons. 9,18,27,36,etc.....are all the same.

 

I had 81 and the program must have screwed itself because it guessed wrong

[Benner]

Simple "rule of 9" trick. Any number subtracted by it's digits will always give you a multiple of 9. Ie 46-4-6=36, 100-1-0-0=99. Hell let's make it difficult. 12345678-1-2-3-4-5-6-7-8=12345642. Then take 12345642/9=1371738. Still a multiple of 9

[SpaceGhost]

Holy shit this is one of the first tricks on the net. Each box with a multiple of 9 is the same thing, Duh.

[RedRocket1647545505]

Simple "rule of 9" trick. Any number subtracted by it's digits will always give you a multiple of 9. Ie 46-4-6=36, 100-1-0-0=99. Hell let's make it difficult. 12345678-1-2-3-4-5-6-7-8=12345642. Then take 12345642/9=1371738. Still a multiple of 9

 

Holy shit this is one of the first tricks on the net. Each box with a multiple of 9 is the same thing, Duh.

 

echo much?

[ericsarge]

had me guessing hardcore...until i read the answer. thanks guys, could have entertained myself for hours.

[99ta]

yeah the wife and I figured it out about 10 min after I posted this. had me for a min though.

[Nitrousbird]

I wasn't paying much attention at first, and I was like "WTF."

 

Then I noticed it was all multiples of 9 had the same answer, and felt let down.