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Probably mind reader

March 11, 2003 08:58 PM


I am sure you may have seen this `Flash Mind Reader' floating around in lots of mails. Basically, you chose a 2 digit number, add the digits and subtract the sum from the number itself. The symbol corresponding to the answer is also displayed by the program. And no matter how random you are at selecting numbers, you always end up with symbols (they being random enough) that are also guessed by the program. But then I am pretty sure, it is just a matter of probability, although it seems hard. I tried not to think logically while picking symbols and found that some of them repeated from time to time. Can somebody try to work out an explanation? Dhar, can you? I'll try myself too.



Comments

31 comments have been added. Add your comments.

1. Ram said...

The final number will be a multiple of 9 always.(for eg. 23 ; 2+ 3 = 5 ; 23 - 5 = 18 ) So I think should have something to do with that.

(btw , what happened to humblog?)

on Mar 11, 09:23 PM | link to this comment


2. Prads said...

I also got this program in my mail and was amazed! But if you try doing the addition and subtraction 4-5 times and then see the result, it's wrong.

BTW, there's a website inspired by this program called mysticball.com

on Mar 11, 09:41 PM | link to this comment


3. Kingsley Jegan said...

Yeah, I worked out pretty much the same explanation. Any number you pick will correspond to a multiple of 9. The script tracks the amount of time taken to pick the symbol (designed deliberately to slow you down), and hazards a guess. Since the guess has a 1/9 chance of being correct, and since it calculates the amount of time taken, the probability of the script guessing the correct symbol approaches 1. But once you deliberately start taking more time, it starts making mistakes.

on Mar 11, 10:03 PM | link to this comment


4. Nilesh said...

>designed deliberately to slow you down
But then even if I select a number, see the answer and then calculate, I find it to be the same symbol. Hows that?

on Mar 11, 10:11 PM | link to this comment


5. Pythagore said...

It has got nothing to do with time. The symbols shift numbers every time - and whatever numbers you choose you will get the same symbol.

For example - on the page I got right now 62 = 62 - (6+2) gives the astrological sign for Taurus. So does 92 = 92 - (9+2). And 27 = 27 - (2+7). And so on. You always get the same symbol! There are only a given set of numbers you can get.

It is really clever. I didn't notice the fact that the numbers switch symbols every time I redid it.

Try for yourself. And give me some credit. :D

on Mar 12, 12:13 AM | link to this comment


6. infinitusrex said...

Exactly. Whatever two digit number you start with, your result can only be one of nine specific numbers:

9, 18, 27, 36, 45, 54, 63, 72, 81.

It's simple math. For every ten numbers the reult is the same. Every number between 20 and 29 will get you 18. Every one between 30 and 39 will get you 27. And the symbol is always the same for the nine numbers.

So the mind reader cannot be wrong. If it comes out wrong, you have made a mistake in your simple calculation. =)

on Mar 12, 12:25 AM | link to this comment


7. (\/)ystic said...

2 digit number:10x+y
Sum of digits: x+y
So diff=(10x+y) - (x+y)=9x

So give all multiples of 9 the same number since your answer has to be a multiple of 9!

(\/)

on Mar 12, 06:48 AM | link to this comment


8. divya said...

Hi
An entry about this exact thing appeared on vyom.org on March 3rd, 2003. I guess it isnt difficult to get the drift if you keep trying it everytime and when u hit the * try again* button u see a different set of symbols. But all multiples of nine have the same symbol ( not identical to the symbol used for the previous try).

on Mar 12, 08:51 AM | link to this comment


9. Arnab said...

um, Mind Reader and everything aside...

Nilesh sir, you seem to be ultra busy... no posts for ages! what's up? when're you coming to Delhi? looking forward to meet! :)

on Mar 12, 08:43 PM | link to this comment


10. Nilesh said...

Oh! This turned out to be too simple! As Mystic shows us the equation which explains everything about this `mind reader' :-)

on Mar 12, 09:39 PM | link to this comment


11. Nilesh said...

Arnab, I am in Agra for now. Trying to secure the Taj Mahal. ;-) No No, just kidding. Actually, I am not that busy. Only, the world has become a bit inaccessible. I don't have the `luxury' of an always-on connection for now. Will come to Delhi soon and will mail you when I do.

on Mar 12, 10:02 PM | link to this comment


12. Dhar said...

Sunil showed it to me and though I dont like bragging, I cracked this in around 5 seconds. No serious, I really did! :))

Most people here have already cracked the solution.

The thing revolves around the figure 9 and its multiples. Everytime the page is loaded
you prolly get some kinda a sessionID like thing. The sytem remember remembers 9, 18, 27.. --> symbol X for sessionID Nilesh or 9,18,27.. --> symbol Y for sessionID Dhar etc.

When you click "Next" it just shows that symbol corresponding to your sessionID. Actually am finding it hard to explain this way, but trust me it is no great deal. But I am sure that is the basic idea.

Love,
Dhar

on Mar 13, 05:44 PM | link to this comment


13. Dhar said...

Hey I really liked Mystic's explanation.

Simple, to the point and something even I could understand. :)

Dhar

on Mar 13, 05:47 PM | link to this comment


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on Mar 25, 04:24 PM | link to this comment


15. MadMan said...

Once you accept the certain premise that the computer can't read your mind, you quickly realise that the result has to be formulaic. And then you discover that it's always a multiple of 9.

But you get different symbols each time. How can that be? Going by our earlier premise, the only explanation is that the script is changing something between tries. Lo and behold! There's your answer.

It's logical, my friend. :)

on Apr 2, 09:14 PM | link to this comment


16. shawn northup said...

okay we picked a number randomly after the picture came up and we didnt even look at the icon yet and it still was right we have tried to trick it and we have failed every time its illogical and we are getting sort of scared.

on Aug 11, 12:38 PM | link to this comment


17. thelonious said...

discovering that the answer will always be a multiple of nine isn't the hard part (unless you think the computer has the ability to read your mind... :-p) if you pay attention to the numbers. the hard part is figuring out why that is the case; some kind of equation.

mystic's equation is really good and it made sense to me instantly. my origional equation was similar, although more difficult to understand:

1X2* - (1+2) = 9
*where 1=the first number of the pair; 2=the second number of the pair; and X is the whole number (i originally used 1 & 2 as subscripts)

this works (although i am not sure that it's founded in mathmatical rules)

one question remains...
why does it work? what mathmatical rule or equation makes this "multiple of 9" theory work???

ps,
the symbols mean nothing... they change everytime just to make you think it's doing more than it is...but the symbols that are at the multiples of 9 are always the same as each other

on Sep 14, 07:30 AM | link to this comment


18. thelonious said...

revision:

in my equation, the answer (9) doesn't mean 9; it's a multiple of 9

on Sep 14, 07:58 AM | link to this comment


19. Yomi said...

i already figured out the secret. if you take any number in one keep trying like 4 of them then you will figure out that when you do all tghe math they all have the same sign for example if you use 23 2+3=5 23-5=18 if you use 99
9+9=18 99-18=81 if you use 10
1+0=1 10-1=9 if you look closely they all have the same sign. see the math thatyou do for all of them they have the same sign.

on May 1, 05:32 AM | link to this comment


20. Yomi said...

i already figured out the secret. if you take any number in one keep trying like 4 of them then you will figure out that when you do all tghe math they all have the same sign for example if you use 23 2+3=5 23-5=18 if you use 99
9+9=18 99-18=81 if you use 10
1+0=1 10-1=9 if you look closely they all have the same sign. see the math that you do for all of them they have the same sign.

on May 1, 05:32 AM | link to this comment


21. Conor Ney said...

Each time your answer will always be the same siymbol and when you press try again. The symbols change, so the answer is different

on May 2, 07:54 AM | link to this comment


22. Conor ney said...

Each time your answer will always be the same siymbol and when you press try again. The symbols change, so the answer is different

on May 2, 07:56 AM | link to this comment


23. Saucemaster said...

pupe

on May 2, 07:58 AM | link to this comment


24. Harami kumar said...

well this program is not what u all think it is it is actually what it should not be an it could be what it should be because it is what it should have been but it is not what it is and it is what it is.......i think it is enough .for u people to get the answer now

on Dec 22, 01:52 PM | link to this comment


25. kyle said...

It's pretty simple. Every Number you pick will end up in a multiple of nine. And if you look at the chart all of the multiples of nine are the same symbol. They change the symbols every time to confuse you.

on May 19, 09:17 AM | link to this comment


26. Jimmy Neutron said...

It is as simple as this:

all 2 digit numbers, when fed into the formula of the mind reader, are multiples of 9.
all multiples of nine on the reader have the same sign, but are changed everytime so it does not look like it is so simple

on Dec 31, 01:35 AM | link to this comment


27. Jimmy Neutron said...

It is as simple as this:

all 2 digit numbers, when fed into the formula of the mind reader, are multiples of 9.
all multiples of nine on the reader have the same sign, but are changed everytime so it does not look like it is so simple

on Dec 31, 01:35 AM | link to this comment


28. zeb said...

if you do 60 or even if you do a number thats easy to add and subtract and then wait a couple minutes it will start to make mistakes

on May 10, 05:35 AM | link to this comment


29. frankie said...

well- the thing is.....
There are two tricks at work here, not just one. If you do the math, you'll see that every possible result has to be a multiple of nine. Any two-digit number can be expressed as a*10 + b. For 73 a=7, b=3. Now the puzzler requests that we subtract the sum of a and b from the number, a*10 + b - (a + b), which becomes a * 9 if you reduce it. Therefore it's a multiple of nine.

2ND HALF OF THE SOLUTION: Note that the glyphs of all the multiples of nine are the same. They are? They are. That's the trick! Every time we refresh the screen the symbols change, unbeknownst to us. It gets better. 90 and 99 which are multiples of nine, have different symbols from the other multiples of nine. But there's no way to get those numbers to come out the other end of the algorithm. Nice twist.

on Jun 2, 05:49 AM | link to this comment


30. Anonymous said...

that's so retarted!!!!!!!!!!!!!!!!!!!!!There's no formular, that's just a trick...anyway...

on Jul 8, 08:54 PM | link to this comment


31. Arun said...

http://artlung.com/words/flash-psychic-proof/ explains everything about it :) . its all multiples of nine and whether you calculate or not(even if you calculate a two digit number with that formula , it comes down to a multiple of nine anyway ) , it shows the same symbol .. and all the multiples of nine have the same symbol . only the other numbers' symbols change each time u click 'try again' making you think it really could read your mind!

Nice trick . Scared me for a while and I googled about it and got the answer .

on Jul 18, 04:40 PM | link to this comment


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