(I) What is the largest 3-digit base ten positive integer such that when multiplied by a single digit, the result is a base ten 4-digit positive integer, with consecutive digits in order (example: 1234, 4567 etc, but not 0123 or, 7968)?

(II) What is the largest 3-digit base ten positive integer such that when multiplied by a single digit, the result is a base ten 4-digit positive integer, with consecutive digits in reverse order (example: 3210, 5432 etc, but not 9786)?

Answer to part one is 864.

Edited on August 20, 2012, 10:27 am

Posted by Chris, PhD on 2012-08-20 10:26:25