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Your Favorite Math/Logic Riddles?
shma asks: "Whether you're involved in the Sciences, Mathematics, or Engineering, you undoubtedly enjoy finding simple solutions to seemingly difficult problems. I'm sure you all have a favorite mind-bender, and who better to share it with than the Slashdot community? Post your own problems and try to solve others. Just one request: If you have figured out the solution, link to it in a post, rather than write it out where anyone can see it." What brain benders tickle your fancy?
"Here's a sample to consider: You're in a dark room with 50 quarters, 18 of which are heads up. You are allowed to move around the coins or flip some or all of them, if you wish. Problem is, it's too dark to tell what you're moving or flipping (no, you can't figure it out by touch either). Your job is to split the coins into two groups, each of which has the same number of heads up coins. How do you accomplish this?"
Is obviously 42
prove that a^n=b^n+c^n for any n.
Turn a light on.
Slashdot - where whining about luck is the new way to make the world you want.
None.
You haul your ass to a bakery, shell out twenty bucks, and get a box or two full of cupcakes, then you go Cid Highwind on everyone.
"Siddown and eat your goddanm cupcakes!"
Striking fear in the authors of godawful fanfiction, I am here, appearing in darkness, Tuxedo Jack!
*** ZOT! ***
Tsunami -- You can't bring a good wave down!
I'm told that it depends upon the price of fish in Tibet on Tuesdays.
Game Overdrive - Gaming News
I met a man with seven wives. Every wife had seven sacks, and every sack had seven cats, and ever cat had seven kits. Kits, cats, sacks, and wives, how many were going to St. Ives?
Rank my idea: http://www.sinceslicedbread.com/node/531
Nobody writes jokes in base 13.
Wow! It's my age! How did you do that?!?
Correct Horse Battery Staple: 72 bits of entropy. Enter "Correct H" into google. When it generates the phrase, that's
I did 3 or 4 rolls and decided to get all intelligent at it and do some pattern analysis, so I fired up excel and solved it whilst waiting. It was something about the wording of the version I saw just gave it away.
The moral is, anything you think you need excel for can almost certainly be done quicker without.
The spinning of the cat's tail allows it to prduce the torque needed to rotate it abotu its center of mass. That or cats are the key to free energy and antigravity *puts on tinfoil hat*
Dear aunt, let's set so double the killer delete select all
Here's a riddle.
It's Saturday night and some geek (sorry Cliff) is desperate and dateless so he spends 3 hours composing a submission, and YES!, it gets accepted by Slashdot just after midnight.
The riddle? How sad is that?
About 5 seconds after the moving end of the rope comes loose.
Hmm...if the 'teenager' is 18 or 19, does that also count as an adult?
Can I switch the statue for one talking bull frog? Cause I know the answer to that one. Pick it up, open one door, throw it down that hall, close door and wait a bit.
Curtesey of The 10th Kingdom
We do not live in the 21st century. We live in the 20 second century.
John von Neumann (1903-1957) [Hungarian/US mathematician and scientist] The following problem can be solved either the easy way or the hard way.
Two trains 200 miles apart are moving toward each other; each one is going at a speed of 50 miles per hour. A fly starting on the front of one of them flies back and forth between them at a rate of 75 miles per hour. It does this until the trains collide and crush the fly to death. What is the total distance the fly has flown?
The fly actually hits each train an infinite number of times before it gets crushed, and one could solve the problem the hard way with pencil and paper by summing an infinite series of distances. The easy way is as follows:
Since the trains are 200 miles apart and each train is going 50 miles an hour, it takes 2 hours for the trains to collide. Therefore the fly was flying for two hours. Since the fly was flying at a rate of 75 miles per hour, the fly must have flown 150 miles. That's all there is to it.
When this problem was posed to John von Neumann, he immediately replied, "150 miles."
"It is very strange," said the poser, "but nearly everyone tries to sum the infinite series."
"What do you mean, strange?" asked Von Neumann. "That's how I did it!"
"just so I'm sure, you can't bash the kings brains in out of frustration using the chalice, right?"
The king knows Kung Fu.
I keep my skills fresh by taking two points and then finding the answer we all know and love with the point-slope form!
a^2 + b^2 = c^2!
Is it cheating to just read the JavaScript at http://www.borrett.id.au/computing/petals-j.htm where you can play the game? I'm not saying its right, becuase I didn't know what the answer should be, so beware.
Software freedom...I love it!
I guess you could say 0^0 = 1, for sufficiently large values of 0. :)
The first prisoner takes the light bulb out of the socket and breaks it so that there are at least 99 pieces of glass. He takes all but 99 of the pieces away. Each prisoner will take one piece of glass away with them on their FIRST time. If they go twice, they don't take a second piece of glass. When there is only one piece of glass left, that person knows that everyone else has been into the room at least once and he can make his assertion.
Solvable by a human with an understanding of the context and an IQ of at least 40: Encrypted: Ner gurer gjb fgnghrf urer?
Letters by guessing: Are t ere t statues ere?
Fully decrypted: Are there two statues here?
f=s
g=t
n=a
h=u
r=e
e=r
When you arrive a son of the coworker answers the door. What is the probability that the other child is a girl?
<answer type="weasel">Zero—the co-worker must have two sons, otherwise the question would say "the son" rather than "a son" ;-)
Need to type accents and special characters in Windows? Use FrKeys
Yes. There are only 3 possibilities, and you've enumerated them all...
I18N == Intergalacticization
I solved it after the first roll. Here's how I did it:
I'm not sure that's how you're supposed to solve it, but Hey - worked for me
The ways of gods are mysteriously indistinguishable from chance.
Wait a minute. Repeat as necessary.
Max: My teacher tells me beauty is on the inside.
Fletcher: That's just something ugly people say.
-- "Liar Liar"
Thank you Captain Obvious. The point of ROT13 is not to keep you from decrypting it, it's to keep you from accidently reading the answer while casually looking at the post.
The king knows Kung Fu.
Shouldn't that be King Fu?
-ba-dum-dum!-
the game involves throwing dice not chairs
Snowden and Manning are heroes.
BTW: Donald Knuth probably hates you.
Best Buy can have you arrested