# Writing the Numbers till N to form a new number

• Mar 24th 2009, 11:14 PM
abhi_dude
Writing the Numbers till N to form a new number
Can the number obtained by writing the numbers from 1 to n in order (for some n > 1) be the same when read left-to-right and right-to-left?

say n=11, the number obtained by writhing the numbers from 1 to n in order will be

1234567891011

We want to check whether it can be same when read from left to right or right to left and if this is not possible can we prove that it is not possible or it is possible

I have tried to form an expression which would give the value of new number formed on powers of 10 . I have tried to form this expression for both forward and reverse numbers and try to see of their difference can be 0. But no success.
• Mar 25th 2009, 01:17 AM
Opalg
Quote:

Originally Posted by abhi_dude
Can the number obtained by writing the numbers from 1 to n in order (for some n > 1) be the same when read left-to-right and right-to-left?

say n=11, the number obtained by writhing the numbers from 1 to n in order will be

1234567891011

We want to check whether it can be same when read from left to right or right to left and if this is not possible can we prove that it is not possible or it is possible

I have tried to form an expression which would give the value of new number formed on powers of 10 . I have tried to form this expression for both forward and reverse numbers and try to see of their difference can be 0. But no success.

This is a very neat problem. But I'm reluctant to give any hints, because this sounds just like the sort of problem that might be set in a math competition. Can you tell us where the problem comes from, please?