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Summing Ones (Posted on 2013-02-27)

Find the sum
1+11+111+.......+111..111(n digits)

No Solution Yet Submitted by Danish Ahmed Khan

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| Comment 1 of 4

an=( 10^n-1 )/9

sn= 1/9(1+10+100+...10^n-n)

sn=1/81*(10^(1+n)-9n-1) W r O n G

correcting my typo:

sn=1/81*(10^(1+n)-9n-10) r i G h T

My original entry was from a smartphone under very harsh conditions

Edited on February 27, 2013, 4:18 pm

Posted by Ady TZIDON on 2013-02-27 11:15:02

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