I have multiplied two 3-digit numbers and coded the whole process twice:

In the 1st coding O replaces an odd digit and E the even.

   OOO
 * EOE
  OEOE
  OOO
 OEE  
 OOOEE 

In the 2nd coding S replaces a digit smaller than 6 and B a digit bigger than 5.

   SBB
 * SSB
  SSSB
  SSS
 BSB  
 BBSSB

Try to get my original numbers(digit 9 does not appear in the multiplication) and all other possible solutions, if any.

(In reply to Not that hard (spoiler) by Steve Herman)

Hi, Steve

1. Assigning a degree of difficulty is a subjective task, usely controversial.

2. I  have "tested" my "double code" by asking two of my math-friends to solve it. It took them over 40 minutes each.

3. Apparently both of them are less gifted or less systematic
or both than you.

4. I agree that the solving is easy , once you grasp the fact that   all B&O dtigits are implicitly defined as 7.

5. Why no one rates this problem?
It is original, thought-provoking and leads to a single solution...

Regards

Ady

Posted by Ady TZIDON on 2011-06-10 05:53:28