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

Home > Probability
The folly of war part 1: Knights (Posted on 2005-08-23) Difficulty: 2 of 5
Consider two opposing armies of knights armed only with swords. The sizes of these armies are 500 and 300 knights.

When locked in combat with an enemy each knight has even odds of winning or losing. Knights, being chivalrous, prefer single combat and will not double up on their enemies. The extra knights in the larger army will wait until there is a free enemy to fight.

[Essentially the killing power of the larger army is proportional to the size of the smaller army.]

When the dust settles the smaller army is eliminated. How many knights (are expected to) remain in the larger army?

Generalize for two armies of size A and B where A>B.

  Submitted by Jer    
Rating: 3.4000 (5 votes)
Solution: (Hide)
This could be as simple as it looks. 300 knights from each side will die, leaving 200 in the larger army. In general, army A will be left with A - B.

You could also consider the problem to be much more complicated. This leads to solutions like Charlie's of just over 300.

Comments: ( You must be logged in to post comments.)
  Subject Author Date
Some ThoughtsPuzzle AnswerK Sengupta2023-09-30 07:43:43
No Subjectbzzt2005-08-30 23:48:51
re: Full generalised derivationCharlie2005-08-28 17:42:36
Full generalised derivationMachiveli2005-08-28 14:24:11
No SubjectPaul2005-08-27 13:16:03
The AnswerJeff2005-08-27 04:31:50
Solution: Yes. Is it Simplifiable? I think not.Dimmeh2005-08-25 09:39:44
No SubjectDimmeh2005-08-25 07:16:12
re: Intuitive SolutionCory Taylor2005-08-24 16:17:25
Intuitive SolutionEric2005-08-24 15:15:19
re: Full manual solution (most probable)Charlie2005-08-24 13:43:13
Some ThoughtsFull manual solution (most probable)Dimmeh2005-08-24 09:04:01
Some Thoughtsre(2): Expected answerDimmeh2005-08-24 08:46:25
Some Thoughtsre: Expected answerFederico Kereki2005-08-23 19:46:44
re: FollyLarry2005-08-23 17:52:05
SolutionTo be more exact. Analogy to smaller case.Charlie2005-08-23 14:02:54
SolutionExpected answerFederico Kereki2005-08-23 12:59:06
Second (continuous, rather than discrete) solutionDimmeh2005-08-23 09:15:44
Another thing to fix upDimmeh2005-08-23 08:44:09
A couple things i should clear upDimmeh2005-08-23 08:40:41
Some ThoughtsNo SubjectDimmeh2005-08-23 08:20:44
SolutionFollyBob Smith2005-08-23 03:15:02
Before the arguments start..Percy2005-08-23 02:48:54
just a guess?sean2005-08-23 02:28:50
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 (14)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2024 by Animus Pactum Consulting. All rights reserved. Privacy Information