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#1 2005-08-25 09:38:27

stef
Member
Registered: 2005-08-25
Posts: 2

Looking for the fifth number

Hi,

for a science quiz I got the following question. Which numbers should be filled in at ...?
137 153 163 127 ...
So obviously we are looking for a number with three digits.
I know the first digit is not 1 (that is why this is not easy I guess) and the second digit is not 7 or 8. My best guess is taking the middle number as the mean and then ... is 235. But this may be far-fetched? who has a better idea?

thanks thanks thanks. Stef;

PS: don't know whether I should view this as a series or as something else?

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#2 2005-08-25 11:23:04

mikau
Member
Registered: 2005-08-22
Posts: 1,504

Re: Looking for the fifth number

not sure I understand the question. Is this an Arithmatic Mean type problem?


A logarithm is just a misspelled algorithm.

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#3 2005-08-25 11:47:51

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,711

Re: Looking for the fifth number

Mathematically you could find lots of things to fit that. A polynomial for example. But it was a Science Quiz, so I expect you are supposed to recognize something.

And how did you know it as a) three digits, b) first digit is not 1, and c) second digit is not 7 or 8 ??

Could we have all the information surrounding it,  please?


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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#4 2005-08-25 19:12:20

stef
Member
Registered: 2005-08-25
Posts: 2

Re: Looking for the fifth number

Thanks to all for your replies. Here is some more information.

Ultimately what I need to do is solve a Sudoku puzzle. However, at start, the sudoku is empty so I need to find numbers to fill in the Sudoku in part and then solve it by logic (as you always would solve a Sudoku). So I am trying to find numbers. Most of them I have already found since the answers to the other questions are more science related. For some answers I am quite sure. That is why I know for instance that on position 2 (the second digit) of my ... (unknown number) it can never be a 7 or 8 since that would put my Sudoku in error (i.e. two times an eight in the same row or two times a 7 in the same box). For the first digit, it can hardly be a one, since this would again contradict with a previous answer of which I am 98 % sure. Oh by the way, I am sure I am looking for a number with 3 digits since the question is prased to find 137 153 163 127... (so three dots) but in addition I know the answer gives me three digits for my Sudoku. I agree that in any case many answers should be possible but with the restrictions above, maybe only one true answer is possible. So I am looking for logical OR mathematical solutions to my problem. Hope this helps. Thanks for your brains. Stef.

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#5 2005-08-29 08:43:40

John E. Franklin
Guest

Re: Looking for the fifth number

Who knows, but I guess 117, so it goes 137 153 163 127 117 173 183 107 97 193 203 87 77...

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