Archive for the ‘Puzzles’ Category
You and a friend have time to kill and lots and lots of Toblerone (thanks Santa!) so you have decided to pass the time by playing a lethal game involving chocolate.
Jack is tossing a fair coin. John believes in gambler’s luck, i.e. that if Jack has tossed more heads than tails so far then the next toss is more likely to be a tail. This way, in the long run things balance out. Jim knows that previous coin tosses have no effect on the next toss. John and Jim start betting with each other on the result of each coin toss. Who is likely to win more of the bets, John or Jim?
100 dwarves are captured by an evil goblin milliner who has an over-abundance of red and blue hats and who really does not like dwarves. Being an evil goblin, he has concocted a fiendish, fiendishly complex game by which he hopes to kill as many of them as possible:
Five hyper-rationalists have been forced to pick a number between 1 and 100. The individual (or individuals) who pick the 2nd highest number is allowed to live, all others are executed by some capricious demon. What number do the hyper-rationalists pick and how many survive?
NB: Me and some friends spent 10 minutes discussing this and could not agree on a solution, is there one?
“Where’s Wally” is a well known children’s (and adult’s!) entertainment. There is a picture. Hidden, somewhere in that picture, is Wally. Alone or together one pores over the book, hunting desperately for the elusive little man. Sometimes people are in a race to find Wally, and the race is won by being the first to point to Wally.
But what if you had to prove that you had found Wally and won the race without pointing to Wally? Maybe your fellow competitor doesn’t want to miss out on the pleasure of finding him themselves. How could you prove to your friend that you had found Wally without them learning anything about where Wally was? Read the rest of this entry »