(1) Take a 3 digit number whose first digit is greater than its last.
(2) Reverse the digits of (1) to create a smaller number.
(3) Subtract the number in (2) from (1) (Add a leading zero if this number is not 3 digits)
(4) Reverse the digits of (3)
(5) Add the numbers from steps (3) and (4)
What is the result, and why?
(In reply to
re(2): Solution  the Fallacy by brianjn)
brianjn does a good job at demonstrating the composition and decomposition of the number for the five steps. It is usually assumed that numbers are decimal (base10), yet it is not necessarily the case (especially in a "trick" puzzle). In base10 the resulting sum for (5) is always 1089. Yet to be more general, in baser where r is an integer greater than 1, the resulting sum for (5) is r^{3} + r^{2}  r  1.

Posted by Dej Mar
on 20130415 15:59:23 