Ok, I am usually pretty good at figuring stuff like this out. But this one has me completely stumped. I figured I'd take it to all the smart people on this board who might be able to give me a clue as to how it works.

Click on the link below and follow the directions. The mystic reader guesses the symbol every time and I cannot for the life of me figure it out!

http://www.mysticalball.com/

I am stumped too, though I did notice that each symbol represents many numbers. Perhaps that is a part of it.

The answer is always a multiple of 9

So 10 - 1 = 9, 53-8 = 45, 92-11 = 81 etc.

So everytime you load up the test, then all the multiples of 9 have the same symbol.

If we take two integers, a and b (between 0 and 9), then any two digit number is going to be 10a + b.

So if the two numbers are 2 and 3, then the equivalent two digit number is 'ten times 2' plus 3. = 23 (or 32 if you swop em around - i.e. ten times 3 plus two.)

So the sum you are trying to do is 10a+b - (a+b )
which is equal to 9a.

Which is why subtracting the sum of a two digit number is always a multiple of 9.

Hats off to Ptarmigan!!

Excellent work Mr. Watson!!

BTW do you do taxes?

Ptarmigan - OMG --- You are so smart. I am really impressed!

What a record-- I post this question and within 2 minutes it gets answered.

Thanks!!

Wait. Just tried the test again. Yes, all the answers seem to be multiples of 9, but not all multiples of nine have the same symbol.

How does it know which multiple of 9 I have chosen???

You're welcome...

If only my debating skills were as good as my math...



Each time you try the test, all the symbols change, but within each test, all the symbols for multiples of 9 are the same. It's a bit sneaky.

Sorry, EXCEPT for 90 and 99, because you can't get 90 and to get 99 you would have to start with a 3 digit number (i.e 100-1).

Then the sum becomes 100a + 10b + c - (a+b+c) which would equal 99a + 9b and the trick no longer works

I tried it, my number was 96 and the first time it did not work~ but every single time after it did...thats kind of strange!

The way that site works is that every possible answer for the formula always has the same symbol. To verify this try 10 different numbers at the same time and notice the answer is the same every time.

To know what answer without trying it ten timeswill come up look at zero.

If definitely got me for a little bit.


Edited to add, not that I bothered to see if this would an old thread with the answer already posted in the thread.