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 Post subject: City Of London - Q 26
PostPosted: Thu Dec 22, 2011 4:15 pm 
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Joined: Tue May 10, 2011 1:12 pm
Posts: 113
Please can someone help us on this question.

A palindromic number is the same whether read it from left to right, or right to left. For example 41514 is a palindromic number.
Find as many whole numbers as you can which are:
a) greater than 1 and less than 500, and
b) palindromic, and
c) either a square number or cube numbers.

All help is appreciated.
Thank you.


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PostPosted: Thu Dec 22, 2011 4:32 pm 
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Joined: Mon Feb 12, 2007 1:21 pm
Posts: 11936
Quote:
Find as many whole numbers as you can which are:
a) greater than 1 and less than 500, and
b) palindromic, and
c) either a square number or cube numbers.


No square number less than 100 is palindromic so I'd list the square numbers great than 100 first

11 squared 121 OK
12 squared 144 no
13 squared 169 no
14 squared 196 no
15 squared 225 no
16 squared 256 no
17 squared 289 no
18 squared 324 no
19 squared 361 no
20 squared 400 no
21 squared 441 no
22 squared 484 OK

now the same with cubes
5 cubed 125 no
6 cubed 216 no
7 cubed 343 OK

So only three numbers I reckon ... 121, 343, 484


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PostPosted: Thu Dec 22, 2011 4:40 pm 
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Location: Watford, Herts
plus 4, 8 and 9.

One can quickly eliminate the 2-digit palindromes by noting they all divide by 11.


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PostPosted: Thu Dec 22, 2011 4:49 pm 
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WP - technically yes but some books do not allow single digits as palindromes.


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PostPosted: Thu Dec 22, 2011 4:58 pm 
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thanks a lot Guest 55 & WP.
You guys are amazing.


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PostPosted: Thu Dec 22, 2011 5:18 pm 
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I'm female btw :D


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PostPosted: Sat Dec 31, 2011 12:02 pm 
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Joined: Thu Sep 30, 2010 11:29 am
Posts: 11
Hi ReplayMum,

Please can you let me know where I can find this paper (City of London)?

Regards

newbie2010


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PostPosted: Sun Jan 01, 2012 9:20 pm 
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Joined: Tue May 10, 2011 1:12 pm
Posts: 113
Hi newbie 2010

If you search for City of London School for Girls in google, you should get the schools link.
Here you can download the papers, but unfortunately there are no answers provided.

Hope this helps.

ReplayMum


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