All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Just Math
UVWXYZ (Posted on 2013-05-27) Difficulty: 4 of 5
Alice and Bob play a game. Starting with Alice, they alternate in selecting digits for a 6-digit decimal number UVWXYZ that they construct from left to right. Alice chooses U, then Bob chooses V, then Alice chooses W, and so on. No digit can be repeated. Alice wins if UVWXYZ is not a prime. Can Alice always win?

No Solution Yet Submitted by Danish Ahmed Khan    
No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)
Hints/Tips re: An approach,etc + hint | Comment 2 of 12 |
(In reply to An approach, no guarantee by xdog)

The answer is YES if you find  U and W s.t. for any UVWX Alice used two of the 1,3,7,9 and can chose  Y such that when Bob adds the last odd digit it is a composite  number.

Hint: think mod 3 first.

  Posted by Ady TZIDON on 2013-05-27 16:31:28
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (1)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2017 by Animus Pactum Consulting. All rights reserved. Privacy Information