Who can work this out?

Thread: Who can work this out?

1. Senior Member
Join Date
Dec 1969
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16,931

Who can work this out?

http://mr-31238.mr.valuehost.co.uk/assets/Flash/psychic.swf<BR><BR>Break the instructions down into algebra and it&#039;s simple to see how it works.<BR><BR>The explanation is below, in hidden text, for people who want to try it themselves.<BR><BR><BR>"Take any two-digit number". Ok, let the digits be "n" and "m" respectively. So the number is:<BR>(10 * n + m).<BR>"Add the value of the digits together". Ok, so that&#039;s:<BR>(n + m)<BR>"Take that from the original number". Ok.<BR>(10n + m) - (n + m)<BR>Which simplifies to:<BR>10n - n + m - m<BR>Which cancels to:<BR>9n<BR><BR>Notice how all the multiples of 9 have the same symbol? That&#039;s no chance. The only POSSIBLE answers to this are multiples of nine. Assuming all multiples of 9 have the same symbol, and it knows the symbol, it can always correctly "guess" the symbol...<BR><BR>Nice and neat. Simple to explain if you break it down mathematically...<BR><BR><BR>Craig.

2. Senior Member
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Dec 1969
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16,931

.

3. Member
Join Date
Dec 1969
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38

But how does it

know which multiple of nine ?????????????????????????

4. Member
Join Date
Dec 1969
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38

lol...nevermind

I got it

5. Senior Member
Join Date
Dec 1969
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11,334

What?

Why do all that? They just change the stupid symbol for all the 9ers each time.<BR><BR>Heh... I like your "invisible" text. I was ready to hold it up to a light bulb and hope it would turn brown.

6. Senior Member
Join Date
Dec 1969
Posts
2,854

RE: What?

I think Craigs algebra lesson was simply to explain the principles behind it, to show WHY its always a multiple of 9.<BR><BR>:-)<BR><BR>

7. Senior Member
Join Date
Dec 1969
Posts
16,931

RE: What?

Yeah - it was basically "once you realise it&#039;s always a multiple of nine, you can see how it&#039;s very easily done...".<BR><BR>Oh well, it amused me for a while.<BR><BR>Craig.

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