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Subject: "divisibility"     Previous Topic | Next Topic
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ranjitr303
Member since Nov-23-10
May-11-11, 01:36 PM (EST)
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"divisibility"
 
   if (A + mX)/(5 or 10)is divisible by m, then A is divisible by m.
also if (A - mX)/(5 or 10)is divisible by m, then A is divisible by m.

eg. is 273 divisible by 7?
ans; to obtain a number close to 273 that is divisible either by 5 or 10 , we can take X= 1 as m=7. then A+mX = 273+7*1=280 WHICH IS DIVISIBLE BY 10. THEREFORE 273 is divbisible by 7.

ranjitr


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alexbadmin
Charter Member
2806 posts
May-11-11, 01:38 PM (EST)
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1. "RE: divisibility"
In response to message #0
 
   >if (A + mX)/(5 or 10)is divisible by m, then A is divisible
>by m.
>also if (A - mX)/(5 or 10)is divisible by m, then A is
>divisible by m.
>
>eg. is 273 divisible by 7?
>ans; to obtain a number close to 273 that is divisible
>either by 5 or 10 , we can take X= 1 as m=7. then A+mX =
>273+7*1=280 WHICH IS DIVISIBLE BY 10.

You probably meant to say that 280 is divisible by 7, right?

THEREFORE 273 is
>divbisible by 7.


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