Change the position of only one number in the sequence given below in order that the amended sequence corresponds to a palindromic sequence.

1, 4, 9, 6, 2, 1, 5, 10, 4

*** Source: Adapted from a problem which appeared in Mensa Canada Website.

Similarly, you could move the first 1 like so:

4, 9, 1, 6, 2, 1, 5, 10, 4

Then you could add a few extra symbols here and there to get:

4, 9+1, 6, 2, 1+5, 10, 4

which becomes

4, 10, 6, 2, 6, 10, 4

Of course, this could be seen as cheating.

Posted by Tristan Nieto on 2008-10-09 13:07:51