Without using any arithmetical symbols (+, -, *, /, or similar; other math symbols; decimal comma or periods; letters; even parentheses) or, in short, anything but the digits, build a number with the digits 1, 3, 5, 7 and 9, that is equal to a number built with the digits 2, 4, 6 and 8 (each digit used once and only once).

Note: This is not a trick. It was extracted from a book edited by Angela Dunn, a mathematician who gathered problems that appeared in many scientific periodical revues!

What if none of the digits are "used up" naming the base?

Define <2468> to be the set of 4 digit numbers consisting of the 4! permutations of 2468.

Maybe one or more numbers in <2468> in some base n where n>8 is equal to a number in <13579> in some other base m where m>9.

Posted by Larry on 2009-05-17 22:40:54