The Grey Labyrinth is a collection of puzzles, riddles, mind games, paradoxes and other intellectually challenging diversions. Related topics: puzzle games, logic puzzles, lateral thinking puzzles, philosophy, mind benders, brain teasers, word problems, conundrums, 3d puzzles, spatial reasoning, intelligence tests, mathematical diversions, paradoxes, physics problems, reasoning, math, science.

Author Message
bonanova
Daedalian Member

 Posted: Mon Feb 25, 2013 10:07 pm    Post subject: 1 Sorry if this question appeared before, I thought I posted it once, but I searched. In any case I don't think the answer has been posted. A girl in a boat on a circular lake is stalked by an ogre on shore who can't swim. She can out-run the ogre and escape if she can get to shore before the ogre reaches her landing point. If the boat can attain 1/pi of the ogre's speed she can win the race to shore by starting from lake's center and heading away from the ogre. The "chestnut" solution to this puzzle is that she can escape with a slower boat - one that attains only 1/[1 + pi] of the ogre's land speed. But that's still faster than the boat needs to be. What really is the minimum boat speed that permits the girl to escape?_________________ Vidi, vici, veni.
esme
Daedalian Member

 Posted: Mon Feb 25, 2013 11:51 pm    Post subject: 2 Hmm, heading straight away from the ogre at each moment seems to give the speed 1/4 which is much better than the 1/pi of keeping the initial heading. So I suspect that a combination of first using a small circle and then heading directly away from the ogre at each moment will give a better value than 1/(1 plus pi), but I dont really see a good reason why this would give the optimal value. In any case, it is never a mistake to use the small circle, and then one should try to find the maximal guaranteed angular distance to the ogre at each radial distance._________________Mundus vult decipi, ergo decipiatur.
 Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year by All usersbonanovaesme Oldest FirstNewest First
 All times are GMT Page 1 of 1

 Jump to: Select a forum Puzzles and Games----------------Grey Labyrinth PuzzlesVisitor Submitted PuzzlesVisitor GamesMafia Games Miscellaneous----------------Off-TopicVisitor Submitted NewsScience, Art, and CulturePoll Tournaments Administration----------------Grey Labyrinth NewsFeature Requests / Site Problems
You cannot post new topics in this forum
You can reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum