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thehalibutkid
Does anyone know how to work out this number? I assume there is some… 
17th-May-2011 09:13 pm
bukkit
Does anyone know how to work out this number? I assume there is some mathematical trickery but don't have the maths fu to work it out. I can offer virtual tea and cuddles to anyone who can answer this for me.

The Number is divisible by eleven and one.

If you divide The Number by two, one will remain.

If you divide The Number by three, one will remain.

If you divide The Number by four, one will remain.

If you divide The Number by five, one will remain.

If you divide The Number by six, one will remain.

If you divide The Number by seven, one will remain.

If you divide The Number by eight, one will remain.

If you divide The Number by nine, one will remain.

If you divide The Number by ten, one will remain.
Comments 
17th-May-2011 08:32 pm (UTC)
11 x 11 = 121
17th-May-2011 08:35 pm (UTC)
Is that a clue? Or am I being dumb?
17th-May-2011 08:38 pm (UTC)
I thought 121 was the answer, but it doesn't work for 7 or 9 :(

Basically, it has to be a multiple of 11, but not of 2-10.

Where is puzzle from?
17th-May-2011 08:41 pm (UTC)
It's for a geocache i've been trying to solve for ages.

http://www.geocaching.com/seek/cache_details.aspx?guid=e120bb8b-3ac3-44fe-8eb7-0f615a7a8bfb

I think it's got 5 unique digits and I know it's lower than 50,000
17th-May-2011 08:47 pm (UTC)
Do you want (what I think is) the answer?
17th-May-2011 08:49 pm (UTC)
Yes please.
17th-May-2011 08:55 pm (UTC)
I think the smallest such number is 25201.

Reasoning: The number one less than this has to be divisible by 2, 3, 4... 10. So if we take all the prime factors of the numbers from 2-10, we get 2, 2, 2, 3, 3, 5, 7 (i.e. you can multiply a set of those together to get any number 2-10). Multiply all of those together and we get 2520, the smallest number with all those prime factors and thus the smallest number which can be divided by every number from 2 to 10. Add one and we get a 2521 which leaves remainder one for each of those numbers.

...except that 2521 can't be divided by 11. But the number we're looking for has to be N * 2520 + 1. At which point I cheated and set up a spreadsheet to calculate (N * 2520 + 1)/11, and the smallest N giving a whole result is 10, giving us a final number 25201. Probably there's some clever way to work out the last bit directly...
17th-May-2011 08:58 pm (UTC)
If it needs to have 5 unique digit, my spreadsheet also gives 80641 (after 52921 as well). But maybe that's too big?
17th-May-2011 09:14 pm (UTC)
Just doing the equasion to see if that's the correct answer.

Would I be right in saying that 5+0+2^2=49? I don't think I am I think it should result in a single digit number.
(Deleted comment)
17th-May-2011 09:36 pm (UTC)
Thankyou. I just got there a second before reading your reply.

But you can also have virtual tea and cuddles should you want them.
(Deleted comment)
17th-May-2011 09:41 pm (UTC)
Yeah well i'm currently sat on my couch with several bits of paper covered in equasions and a headache. I'm still trying to work out how to get there and the answer is actually written in front of me.
17th-May-2011 09:46 pm (UTC)
So anyway how do you take your virtual tea? Should I ever find myself in your neck of the woods I promise to make you a real one.
(Deleted comment)
17th-May-2011 09:51 pm (UTC)
Where are you these days?

And are there any local Geocaches? Cos if there are I don't mind traveling. Seriously my addiction knows no bounds.
(Deleted comment)
17th-May-2011 09:57 pm (UTC)
Well when funds streatch to it maybe you will find a fat dude who looks quite out of his depth in the wastelands wandering around asking if anyone has seen you so he can make you a cup of tea. ;)

Are you registered on geocaching.com?
17th-May-2011 09:34 pm (UTC)
Never mind I was being dumb. It was 5+0+(2^2)=9.

Using the first number that you gave me I created GPS co-ords and they are almost certainly correct.

Therefore your first answer of 25201 is almost certainly correct. The only way to know for sure right this minute would be to go and look at the co-ords on the ground and see if there is a box there. But it's late.

Thankyou so much. I owe you tea (if you want it), cuddles (if you want them) and a favour sometime (just ask).
17th-May-2011 10:02 pm (UTC)
Cool! Glad it worked. And no problem :)
17th-May-2011 09:11 pm (UTC)
LIKE!
10th-Jun-2011 08:16 pm (UTC)
Hey you.....

HAPPY BIRTHDAY
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