Mogmatt16   
Nov 19, 2003
| in case anyone wants to know, this is about a 73.74% chance of living. |
jimbo 
Nov 28, 2003
| Fantastic teaser! Loved it!  Sorry Mog the answer is just as described = 0.74 decimal repeater (74.74%) or precisely 74/99. |
Parsifal
Nov 29, 2003
| I would have placed all my black marbles in either or both bowls first, then placed the white marbles on top of the black marbles in both bowls. Thus when I pick a marble from the top, I would have very close to 100% probability of choosing a white marble.  |
Dazza
Dec 01, 2003
| Hey Parsifal,
I think that if you tried this, the King  would see what you are up to and, being the sadistic SOB that he must be to set this whole thing up in the first place (), he would shuffle the balls around (after you are blindfolded) to put all of the black ones on top. The end result would be almost certain death.  |
Mr_R
Dec 13, 2003
|  a little too obvious for an adult, but maybe interesting for a kid. |
lauramarie
Dec 16, 2003
| Great teaser! |
shadowx8m
Dec 16, 2003
| I like this one and realized that you have even more of a chance of picking the bowl with one white marble. When the emperor moves the bowl you will hear the one marble rolling around in the bowl all by itself and thus know which bowl to pick, the bowl with 99 marbles in it will not do that. |
Golfman072
Dec 22, 2003
| Good Teaser but kind of simple  |
jon0513 
Jan 19, 2004
| that was sort of hard |
BulletThruDaHed
Feb 13, 2004
| Good teaser Made me think. |
pretty_ponyz
Apr 05, 2004
| i totally agree with thongbutt. pink is such a pretty color. i love PINK ponys! |
I_am_the_Omega
Aug 28, 2004
| I was thinking exactly as parsifal was. |
shortstopsmile
Oct 01, 2004
| Which marble did the prisoner choose? |
Infern0
Nov 23, 2004
| That was kinda fun but all u ppl who did the math have must have been bored. |
badjoorimikhame
Dec 16, 2004
| one white in a bowl and the rest in the other.the chance to win would be nearly 75% |
pi202
Dec 16, 2004
| Hey infern0, you don't need to be bored to do most maths, just interested! Anyway, the maths in the this teaser took less than a minute, so you didn't even need to be that interested! |
Mogmatt16
Dec 16, 2004
| Why does it always seem as those who want you dead are so willing to let you live on some obscure technicality?  |
Tiggr
Dec 16, 2004
| That is a puzzling question that even the sadistic person that I am can't even answer Mogmatt16  But this was a good early morning breakfast side-dish teaser. |
Sreenadh
Dec 16, 2004
| Guys, I don't think the answer is correct. Your probability is still 50%.
Basically, you are asked to chose Marbles, not bowls and then marbles. If you list all possible outcomes eg: Bowl1,White; Bowl2,black; Bowl2,white; etc., you see that you still have 50 right choices and 50 wrong ones. |
jimrcook
Dec 16, 2004
| Sorry, Sreenadh, it's not 50%. The teaser says "You then can choose one bowl and remove ONE marble." When you pick a bowl, you have a 1/2 chance of getting the "white" bowl. If you get the "mixed" bowl, you have a 49/99 chance of getting a white marble. The total probability of living is the sum of all the other probabilities, namely (1/2 times 1) + (1/2 times 49/99). To show the work after that is 1/2*1 + 1/2*49/99 = 1/2 + 49/198 = 99/198 + 49/198 = 148/198 = 74/99, or the ~75% mentioned in other comments. A Monte Carlo program verifies this answer. |
I-20
Dec 16, 2004
| You can separate the blackand white marbles |
ybbuw3
Dec 16, 2004
| As you blindly reach for the bowls, make sure to lightly bump both bowls. Simply select the lightest bowl and win. |
(user deleted)
Dec 16, 2004
| I disagree with the answer. Your probablilty would be even better putting two white marbles in one bowl, then you would have a 100% if picking from the light bowll and 50/98ths from the heavy bowll. This logic can be carried as far as one can distinguish the two bowls, to the limit of having 50 black+1 white in one bowl and 49 white in the other. Then one would have a 100% chance if given the light bowl (and you can discern that it is light) and a 50/51th chance of being correct with the heavy bowl. This gives approximately a 99% chance for survival and future revenge against the king.
|
eyecue
Dec 16, 2004
| Dwarf...how do you figure? If you have 2 white marbles in one bowl, the the ratio of black to white in the other bowl is not 50/98. You only have 50 white to start with (unless the king is really evil and sneaky), so if you seperate 2 of them you would have a 48 out of 98 ratio in the other bowl. Your breakdown would be this: bowl 1 - 2 white, Bowl 2 - 48 white, 50 black. 2+48+50=100 marbles, 98 of which are in bowl 2. |
I_am_the_Omega
Dec 16, 2004
| Maybe he read the question wrong? lol.. |
shm87funny
Dec 16, 2004
| this one was pretty interesting, and yet triky. I like it. Nice work. |
fastfingers
Dec 16, 2004
| Why couldn't you divided the black marbles in half and leave the white ones intact. That way no matter how many are in each bowl you will know to choose the whole marbles. It said you can divide the marbles anyway you want!!! |
icepenguin13
Dec 16, 2004
| fastfingers i dont think thats what she meant but good answer, you really have to think outside the box for that one and great treaser pete!! |
brokenbeenie
Dec 16, 2004
| The riddle was easy for me, but thinking as a sinister king would think, which is what he would have to be to think this whole thing up....he would make sure that there wasn't any chance of you getting the white marble....think about it! Either way you divide the marbles if the king wants you dead..he wants you dead. |
(user deleted)
Dec 16, 2004
| no matter how you do it it's a 50 50 chance |
passion
Dec 17, 2004
| Who cares about the math of this teaser , you have to admit that it is a good one!  |
moomeows
Dec 17, 2004
| but why can't you divide both black and white marbles equally in both bowls but start with all the black marbles at the bottom and the white marbles on top so you still have a 50/50 chance to pick a white marble? I liked the teaser because it had different possibilities. |
aprilapineru13
Dec 17, 2004
| yeah, we had one'o'these on an algebra test once. only it had bottles of poison. good teaser. but some'a yall had some pretty clever alternate answers.
by da way, mooses say quack just like piggies |
unmellowyellow
Dec 20, 2004
| very good teaser!!! but an EASY ONE!! |
tommo
Jan 11, 2005
| Classic! I love the probability ones. |
tiptoes007berbs
Jan 20, 2005
| good one! |
naviana
Jan 29, 2005
|  its nice but i thought that it would be 25 black marbles and 25 white marbles in each bowl |
brianz
May 07, 2005
| Good teaser!
I didn't read the problem carefully enough and thought and thought each bowl had to have 50 marbles. |
iblondhaha
Jun 13, 2005
| that was interesting, it's a good answer but i didn't even get close . . . oh well, good job |
mrbrainyboy
Dec 17, 2005
| Love it! Hope you got white! |
mogur
Dec 17, 2005
| If the sun is shining, pick a cooler marble. If it isn't, put all the black ones in your pants for a few minutes before putting them back in the bowl. |
jessjspieks
Dec 17, 2005
| I think if you just put one white marble in 1 bowl, 99 in the other bowl, u are guaranteed to win. Your answer is too complicated i think |
kick
Dec 17, 2005
| smart |
bluehawk
Dec 17, 2005
| Good teaser Mogmatt, i liked this one |
shawneeo
Dec 17, 2005
| This kind is too hard for me, I have some kind of strange resistance to percentages, but I appreciate it, Thanks!  |
kayleeskitties
Dec 17, 2005
| Good teaser. I thought that he would have just put the white marbles on the top so he would know that the tops ones would equal life.... |
gillt13
Dec 17, 2005
| Like it!!! Couldn't work it out (no good at maths problems ) but I enjoyed the challenge!!! |
tbech7430
Dec 17, 2005
| Great teaser! But I think you have a 50/50 chance anyway you split them. |
smee
Dec 17, 2005
| Heh heh... it doesn't look like that king was very bright. Ok, so he decides you should have a 50/50 chance to live. Wouldn't it have been simpler... and CHEAPER... to just flip a coin instead of going out to buy all those friggin' marbles? Also, the teaser didn't say whether you had to mix up whatever combination you chose... I'd just pour all the black marbles into each bowl first, and then pour all the white ones on top of all the black ones. And then just pick a TOP marble. |
crzyness4lyfe
Dec 17, 2005
| nice! i liked that one! good job. |
lindquist_25
Dec 17, 2005
| It was ok, but kind of boring. Another way would have been to put a white marbel in one bowl and the rest in the other. Then just pick the marble out of the one that you know only has one marble, and you will for sure live. |
hidentreasure
Dec 17, 2005
| Easy |
KNIGHTTEMPLER
Dec 17, 2005
| if you put 25 black on bottom and 25 white on top you live |
gummybearbkakey
Dec 17, 2005
| dat was preety cool..keep it up |
Punk_Rocker
Dec 17, 2005
| Woo Hoo I got it! |
(user deleted)
Dec 17, 2005
| there is a better way... put 25 black in each bowl the put the white ones on top... no matter which bowl you choose, the white ones are on top |
shopaholic918
Dec 17, 2005
| I think thatwas agood one! But whih bowl did eh choose from after all?
|
gali
Dec 17, 2005
| nice one |
overnormal
Dec 17, 2005
| The weight of the bowl with 99 marbles would be 99 times greater than the other--at least I think?! Great fun. I love this sight! |
katiebug
Dec 17, 2005
| simple and fun! Great job! |
kman613
Dec 17, 2005
| couldn't figure it out, but loved trying! great one |
Y_M_A_05
Dec 17, 2005
| that one wasn't a very hard one |
mrtickles
Dec 17, 2005
| I liked this one--yeah it was easy, but those are the best ones. |
smosaka
Dec 17, 2005
| Definitley a great teaser....you guys say it was easy? Guess I'm just stupid....  |
mimigolfer
Dec 17, 2005
| thought it was fun and some of you....jimrcook....really need to relax and just enjoy the teaser. |
LOVENUGGET
Dec 17, 2005
| WOULD'NT IT BE ALOT EASIER IF EACH BOWL HAD 50 OF EACH COLOR? ALL YOU HAVE TO DO IS PUT ALL THE BLACK MARBLES ON THE BOTTOM IN EACH BOWL. |
beerexs
Dec 17, 2005
| At first I thought to put 25 white and 25 black in one bowl and then to put 25 whites and 25 blacks in the second bowl |
Lucasgal
Dec 17, 2005
| It was ok. Alot of fun when you can figure it out. I did so it wasnt too hard. |
POPS
Dec 17, 2005
| Loved it and I got Makes a lot of SENSE!!!. A FAVORITE |
smee
Dec 17, 2005
| I still think I like the idea of the 25 black marbles on the bottom of each bowl, and the 25 white ones on top...... (which I suggested 22 comments ago!!)... However, I think this was a teaser to get you to use mathematics to determine probability and outcome. Math was NEVER my strongest subject in school. |
settra626
Dec 17, 2005
| |
wordlover
Dec 17, 2005
| Probably shoulda had five cups of
coffee before trying this teaser!
NICE ONE!!!!! |
christine77
Dec 17, 2005
| A good teaser, I think there are a lot of different ways to solve this. I think everyone has their own idea, I was thinking the 25 bottom top thing, but the answer was good also. Anyway, fun teaser, I love these.... |
kimberlykay
Dec 17, 2005
| The only problem I can see with the 25 white on top and 25 black on bottom would be the size of the bowl. If the bowls are extremely large and the marbles are small then it wouldn't be possible to place them upon each other. I think we must rely on the math here. |
kimberlykay
Dec 17, 2005
| Oh, by the way, I like this teaser even though I am not a fan of percentages or math. |
babycakes
Dec 17, 2005
| you could have put 25 black marbles in each bowl(on the bottom), and 25 white on top, becouse they said mix the bowls around ,not the marbles.the whie ones would be right on top. |
shawneeo
Dec 17, 2005
| All the answers involving choosing the light bowl with one in it and taking the top marbles depend on things we don't know. Maybe the person had to just point at one of two spots, so would never get to feel if the bowl was heavy, hot, cool, light, etc. Then when they mixed the bowls around, if they did it with enough force all the top/bottom marbles would get mixed together, so you can't rely on that either. |
moimeme
Dec 17, 2005
| loved this one! fun. way cool. What's with the obsession of marbles on top/bottom? Have you ever tried to "stack" marbles? Wouldn't the size of the bowl matter? To those who ask why those who want to kill give such chances-- great question---lol! Maybe the emperor wants the chooser to live.
Maybe emperor is bored & has nothing better to do with his time but think up absurd punishments-- just to see what happens. Ultimate power corrupts. |
(user deleted)
Dec 18, 2005
| umm... wouldnt the king/emporer (sp) just mix the bowl of marbles up... it doesn't say he cant... (if you put the white ones on the top and the black ones on the bottom) |
juliecat10
Dec 19, 2005
| cool... |
formation007
Dec 19, 2005
| Great teaser, these are the kind of teasers that are best because they make you think and after viewing the answer, you are either kicking yourself that you didn't get it or pleased with yourself that you did. Unfortunately, i do not have much experience with the latter. Once again, good teaser. |
ragethe3rd
Dec 20, 2005
| Ahh too much pressure! |
luvias
Dec 22, 2005
| This is a great teaser i loved it! |
rose_Luv_heart
Jan 06, 2006
| that was fun 'n easy I learn that in class already sorry but i still liked it |
teen_wiz
Feb 09, 2006
| That was awesome! Going in my faves! |
SPUTNIK2
Feb 22, 2006
| that was da bomb! |
JessicaLynn
Mar 26, 2006
| I thought that if you put one white in one, and in the other bowl put the whites one top you would get a better chance. |
Vigo95
Apr 15, 2006
| i love this !!!!!!!!!!!!!!!
i thought it was just great ! |
AbsurdHero
Dec 17, 2006
| I got this right, but not for the same reason as in the official answer. I didn't think about the "choose one bowl" aspect as I walked to the bathroom, therefore I was thinking it would be easy to feel around, test bowl weight, or listen and tell the difference between 1 marble and 99. |
Kiroko
Dec 17, 2006
| What if you were to put all the black marbles on the bottom and then cover them with the white marbles, or is the emperor mixing the marbles around before letting you choose? |
puttumup
Dec 17, 2006
| waste of time |
puttumup
Dec 17, 2006
| : |
nu_rob_roy
Dec 17, 2006
| You gotta love puttump or Imurry's self-valuation...As for the teaser, it work, simple and fun. Thank you. Good on you. |
Pizzazz2u
Dec 17, 2006
| A very entertaining teaser. If you have to go through ALL of the math, ALL I can say is, you are not having fun... This kind of teaser has been around for ages, quit arguing for and against and have fun with it, or just totally hate it, and *Go away* Sheesh! BTW. a Totally Awesome Teaser. Have a marvelous day, Everyone! (or else enjoy the hatred of lmurray and family..lol)~ |
becky18567
Dec 17, 2006
| i didnt get it. thats kind of sad |
lmurray
Dec 17, 2006
| BU TAI HAO! (NOT TOO BAD!)
INTUITIVELY EASY, OBVIOUSLY, BUT I AM SURE THERE ARE SOME PEOPLE OUT THERE WHO HAVE NEVER SEEN THIS BEFORE.
ANYWAY, NOT BAD. TKS. |
ragdol13
Dec 17, 2006
| OR you could put all of the whites in one bowl and all the blacks in one bowl... |
bradon182001
Dec 17, 2006
| Have to agree with Pizzazz. BTW I did get the official answer. |
jabdr
Dec 17, 2006
| KEWL |
OhEmGee
Dec 17, 2006
| liked it! i didnt get it but once i read the answer i was like wow that makes sense!
lol i would love to see more |
vlerma
Dec 17, 2006
| I had a hard time with this one because I kept thinking of being blindfolded and having 2 empty bowls. And I was supposed to sort the marbles which I could not see whether they were black or white. Hummmm. Needless to say I didn't get it. Thanks for submitting tho. |
krystalklearsky
Dec 17, 2006
| good teaser |
yesenia8rivera
Dec 17, 2006
| That was a pretty awesome teaser but I've never been good with probability Even though I did get it wrong it was still pretty enjoyable though KEEP UP THE GOOD WORK!!! |
I_Write_Books
Dec 17, 2006
| Good teaser...basic logic, but still fun. I think the people who are getting confused are just misreading and misunderstanding the answer. |
varie4ever
Dec 17, 2006
| HORRIBLE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!  |
coachpisco
Dec 17, 2006
| I think I'd have to go with 25 and 25 |
breathesunshine
Dec 17, 2006
| I was one of those that went with putting the black marbles on the bottom and the white on top. It's fun to read how other people wrapped their minds around this and came up with different answers. Just goes to show you that everything is not always "black and white"! |
Cat-Lady
Dec 18, 2006
| 50/50 chance was the best I could do 25 of each color in each bowl and alot of praying |
Qrystal
Dec 19, 2006
| I actually played around with math a bit before the answer finally occurred to me, and my mathematical intuition told me that it was most certainly the right answer for the right reasons and I didn't even take the time to mathematically prove it to myself (after all, this is just a teaser, not a math test!)
I was not surprised to see suggestions regarding temperature of the marbles; I was pleasantly surprised to see the unique and clever suggestion about splitting the black marbles in half; I was appalled at how many people thought that stacking the white marbles on top would increase their chances. Maybe, just maybe, it would help to put the white marbles around the edges and the black ones in the middle. But I would imagine that the emperor is testing whether he should spare a smart guy's life, or put to death a smartass.
Anyways, it goes to show that you just never know when math might save your life. Yarrr. |
mmmcla01
Dec 19, 2006
| Clever!! |
RRAMMOHAN
Dec 20, 2006
| Great teaser, but those who have some exposure to probability theory would find this quite an easy one. |
patzyboi
Feb 19, 2007
| i was thinking for of crapping and putting the crap on the black ones |
cowman12
Mar 21, 2007
| Fun and easy!!! |
(user deleted)
Mar 27, 2007
| you also could put 50/50 in both bowls....putting the whites on top on both of them making the chance a 95% that you will live...... |
animaru2413
May 24, 2007
| Even with those odds, i would still hate to be that guy! |
(user deleted)
Aug 16, 2007
| There is a much simpler way to guarentee that you live. Put one white marble into one bowl, and put the rest in the other bowl. When he asks you to pick one, feel the amount of marbles in both bowls and pick the marble from the bowl that only has one in it. Simple. |
javlad27
Sep 16, 2007
| no, princerocker, you have to select only one bowl, you can't feel both of them |
(user deleted)
Dec 02, 2007
| if we place y marbles containing x white marbles in the first bowel then the chance of picking a white marble is:
1/2 * (x/y) + 1/2 * ((50-x)/(100-y))
such that 0 < x < 50 and 0 < y < 100
Find x,y satisfying the constraint above that will give the maximum value of this expression using Lagrange Multipliers. |
mathgrant
Nov 18, 2008
| While I enjoy some of the "outside the box" solutions (particularly the one involving splitting the black marbles in half!), let's assume that a random bowl is chosen, and a random marble is chosen from that bowl, with no opportunity for outside-the-box thinking. An easy way to prove that a distribution of 1 white marble in one bowl and the other 99 marbles in the other is optimal is as follows:
Maximizing your chances of picking a white marble is the same is MINIMIZING your chances or picking a black marble. The minimum chance of choosing any particular black marble is 1/99, which is achieved if and only if said black marble is in a bowl of 99 marbles. With a distribution of 1 white marble in one bowl and the other 99 marbles in the other, every individual black marble has this minimum chance of being drawn, so the overall chance of drawing one is also clearly minimized. QED.
As for the complaints of "why would an emperor give you an almost 75% chance of living?": Hey, this is a math puzzle, not an attempt at realism. |
BNL101
Nov 26, 2008
| I thought about rearranging the marbles in tight horizontal rows and having a white or black on the right and left side of the bowl. |
Paladin
Mar 13, 2009
| I loved this one... got it right, but my probability calculation is different than most. In my calculation, I found the total probability of drawing a white marble as 1/2 + 1/2(49/99) = (198 + 9 / (2 * 19 = 296/396 = 74.74747474... = 74.75% |
dalfamnest 
Oct 10, 2009
| Really good - thanks! I've tried a lot of probability questions and this was fun. I agree with your solution. 0.747474... is also correct.
I wonder if there ever were rulers, such as feature in these diversions, who, having nothing better for amusement, gave such straws for prisoners to clutch at!! |
hjordis
Dec 17, 2009
| I suck at probability, but I instinctively figured out the correct answer in about 3 seconds. Fun problem though. |
kaaozz
Dec 17, 2009
| I lived. If you place 1 white marble in 1 bowl and the other 99 in the other bowl . T |
kaaozz
Dec 17, 2009
| Youre chance of survival is 100% . Place one white marble in 1 bowl the other 99 in the other bowl , then simply choose the lighter bowl. The teaser spefically says you get to choose the bowl . |
auntiesis
Dec 17, 2009
| With this kind of evil king, you get to choose the bowl by pointing to the left or right, not feeling the weight of the bowl. That said, you now have no chance to weigh the bowls. My answer was intuitive, and it was correct. Amazing for me. Great teaser, fun and doable even without all the math. Loved it. Thanks. |
jcmoore2112
Dec 17, 2009
| You would have slightly less than 75% if you put one white in one bowl and the rest in the other. However if you split them 50/50 in each you would have exactly 75% which would be greater. |
Wyrmwood
Dec 17, 2009
| "Mix the bowls" implied that the marbles could be remixed (at least to me). I would have understood the quiz had it said the emperor can "swap the two bowls". |
doehead
Dec 17, 2009
| If he was a prisoner, that means he had already lost his marbles!!!! |
leroyleroy
Dec 17, 2009
| THIS ONE IS OVER MY HEAD. I GUESS I HAVE LOST ALL MY MARBLES!!!!!!!!!!!! |
gargph
Dec 17, 2009
| I didn't read the question properly, so my answer was just keep 1 white marble, distribute the rest randomly, and secretly pretend that you chose the white marble that you took |
beyonce123
Jun 02, 2010
| In one bowl put 1 white marble. In the other bowl put 50 black marbles at the bottom and 49 white marbles at the top. feel around at the top. If you feel amarble take it. If you don't go down to the bottom and pick that marble. 99% foolproof |
yokouhoho
Apr 24, 2011
| awesome teaser! |
Babe
Dec 17, 2012
| Am I the only one who has heard this one before? It is really an oldie, but then so am I and that is probably the reason I have heard it a long time ago! It has been around a while. |
cutebug
Dec 17, 2012
| Right on Babe. This one was originated by Moses. |
Casnie
Dec 17, 2012
| I have another answer:
Just put 25 marbles at the bottom of each bowl and cover them with 25 marbles each . You have a 99.9% chance of living. |
spikethru4
Dec 17, 2012
| No Casnie, that's the same answer that dozens before you have come up with. And it's just as wrong as the others because (a) you don't know the size of the bowl, and (b) you can't guarantee that the marbles won't rearrange themselves when the bowls are mixed. |
DarylK
Dec 18, 2012
| In regard to the very first comment; it is not ~74%. It is 51% based on the answer.
Use a probability tree, and surely it will suggest the following:
Probability of picking:
X = Bowl 1
Y = Bowl 2
W = White marble
B = Black Marble
P(A)*P(W|A) + P(B)*P(W|B) = P(LIFE)
(1/2)*(49/49) + (1/2)*(1/51) = 51%
51% chance of picking the white marble, ladies and gentlemen. |
DarylK
Dec 18, 2012
| Sorry guys, here' my comment, revised:
In regard to the very first comment; it is not ~74%. It is 51% based on the answer.
Use a probability tree, and surely it will suggest the following:
Probability of picking:
X = Bowl 1
Y = Bowl 2
W = White marble
B = Black Marble
P(X)*P(W|X) + P(Y)*P(W|Y) = P(LIFE)
"Place 1 white marble in one bowl, and place the rest of the marbles in the other bowl (49 whites, and 50 blacks)."
Translated mathematically yields:
(1/2)*(49/49) + (1/2)*(1/51) = 51%
51% chance of life, ladies and gentlemen.
Please DO message me if I am wrong and why.
Thanks. |
spikethru4
Dec 18, 2012
| Not sure where you're getting your probabilities from, Daryl, but the probability of choosing a white ball from the two bowls are, respectively, 1/1 and 49/99. Since there's a 50% chance of choosing either bowl, the probability of life is, as explained much, much earlier in the thread, (1/2)*1 + (1/2)*(49/99) = 74% |
