You have 9 golf balls. 8 of which are equal in weight. The ninth is slightly heavier then the rest. You also have a balancing scale. Can you use this scale two times and only two times in order to tell which ball is heavier?
...and a joke:
A little kid walks into a city bus and sits right behind the driver and starts yelling, ''If my dad was a bull and my mom a cow I'd be a little bull.''
The driver starts getting mad at the noisy kid, who continues with, ''If my dad was an elephant and my mom a girl elephant I would be a little elephant.''
The kid goes on with several animals until the bus driver gets angry and yells at the kid, ''What if your dad was gay and your mom was a prostitute?!''
The kid smiles and says, ''I would be a bus driver!''
<i><b>Artificial intelligence will never be a match for natural stupidity</b></i>
roflmao!!! That second one is great.
In a world without <font color=red>walls </font color=red>or <font color=green>fences </font color=green>, what use have we for <font color=red>Windows </font color=red>or <font color=green>Gates.</font color=green>
Divide the nine golf balls into three groups of three. Weigh two groups. Whichever group is heavier contains the heavier ball, or if both groups weigh the same, the heavier ball is in the third group.
Take the group containing the heavier ball and weigh two of the balls. If they weigh the same, the third ball is the heavier one, otherwise the scale will tell you which one is heavier.
Yeah? Well if my Aunt had balls she'd be my Uncle.
Well done.
Did you figure that out, or did you get some help from a <font color=green> lizard<font color=black>?
Wingding - the guy your mother warned you about
One of my <b><font color=green>lizards</b></font color=green> helped me remember that I did that problem before in highschool. It took me a bit to remember how.
Yeah? Well if my Aunt had balls she'd be my Uncle.
....*sigh of admiration*....<font color=green>Lizards<font color=black>....is there anything they CAN'T do?
Wingding - the guy your mother warned you about
They can't give me head. I won't let them. Their teeth are to sharp.
Yeah? Well if my Aunt had balls she'd be my Uncle.
That's fair. They are still amazing.
This post will elevate me to Ancient Poster. I dedicate this post to the might of your <font color=green>lizards<font color=black>.
Wingding - the guy your mother warned you about
Thats a lot of posts.
<font color=blue>If you have extra parts left over, that means you put it together right!</font color=blue>
Every time I masturbate, I enter a post. That's the kind of sad existence I have. My computer monitor and keyboard are a right mess.
Wingding - the guy your mother warned you about
How many times do you rub one out a week? is it normal to do it about 10~15 times a week?
Yeah? Well if my Aunt had balls she'd be my Uncle.
I score that many in an afternoon.
Wingding - the guy your mother warned you about
Respect! and well done!
So here is an update (this is relatively easy, but its just a midway landing to get to the real challenge
):
You now have 12 golf balls but are allowed to use the scale 3 times. 1 golf ball is still a bit heavier than the remaining. How do you go about that?
<i><b>Artificial intelligence will never be a match for natural stupidity</b></i>
That would be 3 groups of 4. The first weigh would leave 4 balls (shush Wingding!). Then you weigh 2 and 2, giving you the 'heavy pair'. Then you weigh the pair to get the heavy one.
That one was easy!
<b><font color=blue>~ <A HREF="http://www.btvillarin.com/phpBB/viewtopic.php?t=324" target="_new">My System Specs</A> ~<font color=blue></b>
good job cammie
Yeah? Well if my Aunt had balls she'd be my Uncle.
Yes, I told you. So here is the REAL challenge. Whoever solves this will be rewarded with extreeme respect and WELL DONE!
The challenge is basically the same. You have 12 golf balls, and are allowed to use the scale 3 times. BUT, you do not know whether the deviating golf ball is heavier or lighter than the rest. Using the scale 3 times, you have to point out the deviating ball AND tell whether its heavier or lighter than the rest.
Is this at all possible? And how do you do that?
<i><b>"I don't understand what it is! Let me kill it!" -- Worf</b></i>
No it's not possible.
(easy answer).
BTW my Dad had a great suggestion for the first one. Do 4 and 4. Then do 2 and 2. When you have your last pair, put one in each hand and decide!!!
<b><font color=blue>~ <A HREF="http://www.btvillarin.com/phpBB/viewtopic.php?t=324" target="_new">My System Specs</A> ~<font color=blue></b>
Right I've had a look at this...
I don't think it is possible.
Take 3 groups of 4 and do the last one. At the end of the third weigh, you have two balls, but you need a 4th weigh to tell which is the deviant.
Take 6 and 6 as your first weigh. You have no way of knowing which 6 is the deviant 6. Needs I think 5 weighs to do this.
Am I right?
<b><font color=blue>~ <A HREF="http://www.btvillarin.com/phpBB/viewtopic.php?t=324" target="_new">My System Specs</A> ~<font color=blue></b>
Well, I think its too soon to disclose whether or not its possible. You'll need to do some more thinking
<i><b>"I don't understand what it is! Let me kill it!" -- Worf</b></i>
If you divide them into three groups of four you can determine whether you have a heavy or a light ball by weighing to and observing and then weighing the third set with one of the other two. If the first two are the same then the odd ball is in the third group but you do not know if it is heavy or light. So you weigh it with one of the other groups. From that you can determine if it is heavy or light. After that you take a the set that has the heavy/light ball and weigh those in pairs of two. From that you can determine which of two balls is heavier/lighter. After that, since you are out of scale uses, you take the two with different masses, mount them on a quartz strand with two large masses around the mass. Measure the force on the balls due to the gravitational constant and from that you can determine which ball is heavier/lighter. And best of all you only used the scale three times.
In a world without <font color=red>walls </font color=red>or <font color=green>fences </font color=green>, what use have we for <font color=red>Windows </font color=red>or <font color=green>Gates.</font color=green>
Nice try
. But your gravity trick is also a kind of measurement, and only 3 of those using the scale are allowed.
And ofcourse, there is a solution. I wouldnt post an impossible riddle.
<i><b>"I don't understand what it is! Let me kill it!" -- Worf</b></i>
4 groups of 3. Weigh two of them to eliminate 6 balls.
Weigh one of the eliminated groups of 3 with one of the suspect groups of 3, to detemine which is the rogue group.
Finally taking into account the movement of the scales on the first and second weighings, weigh 2 of the rogue 3 to get your results.
I get the feeling it's not that easy.
<b><font color=blue>~ <A HREF="http://www.btvillarin.com/phpBB/viewtopic.php?t=324" target="_new">My System Specs</A> ~<font color=blue></b>
Nice try. But this method wont work in all situations.
| Quote : 4 groups of 3. Weigh two of them to eliminate 6 balls.
|
If your first weighing gives you equilibrium, the deviating ball is among the remaining 6. In this case you dont have a suspect group of 3.
<i><b>"I don't understand what it is! Let me kill it!" -- Worf</b></i>
You then weigh 3 of the suspect 6 with 3 of the equilibriem 6. That will give you the 3.
<b><font color=blue>~ <A HREF="http://www.btvillarin.com/phpBB/viewtopic.php?t=324" target="_new">My System Specs</A> ~<font color=blue></b>
Forget it. If you get equilibiem on the first two weighs, you can't do it. You're left with 3 balls. If the third weigh produces non-equilibriem, you're stuffed.
<b><font color=blue>~ <A HREF="http://www.btvillarin.com/phpBB/viewtopic.php?t=324" target="_new">My System Specs</A> ~<font color=blue></b>
Yes. With that approach you sometimes will need more than 3 weighings (this words sounds suspeciously wrong).
I will give you a hint: When you weigh some balls, you not only gain information about the balls on the scale, but also on the balls you don't weigh. But I sense from your attempt that you already figured that out?
<i><b>"I don't understand what it is! Let me kill it!" -- Worf</b></i>
Yup. I'm gonna go to bed now! [/huffy stroppy sulky kid]
I shall mull over it in my dreams and on the road tomorrow morning. By lunchtime I will either have the answer or a suitable childish response!
<b><font color=blue>~ <A HREF="http://www.btvillarin.com/phpBB/viewtopic.php?t=324" target="_new">My System Specs</A> ~<font color=blue></b>
U'r allowed to weigh 3 times, right? 4 groups of 3.
Weigh first 2 groups. If they give equilibrium, weigh next 2 groups. Then on the 3rd weighing, whichever group has the heavier, take the 2 balls and weigh em against each other. Thus one will either be heavier, or the reamining one not weighed will be the heavier. With this approch, it can be done in even 2 steps sometimes.....
1*** 2*** 3*** 4***
weigh 1*** vs 2***
if 1***weighs same as 2***
weigh 3*** vs 4***
whichever is heavier, take 2 balls from and weigh against each other X* vs X*
if both r at equilibrium, X* u left out is it, otherwise heavier is it.
If 1***!=2***
do same approch where u weigh 2 balls.
What if you had admin rights to life?
Your approach only works if you know that the deviating ball is heavier than the remaining. This (easier) variant was solved by camieabz a few posts back.
Remember, you do not know whether the ball is heavier or lighter. Only that it deviates.
<i><b>"I don't understand what it is! Let me kill it!" -- Worf</b></i>
O, I see.
What if you had admin rights to life?
There are ten bags containing marbles. Each bag has at least 10 marbles in it. Nine of the bags contains only marbles weighting 10 grams each. One of the bags contains only marbles weighing nine grams each. Each bag has a different number of marbles in it. All of the marbles look exactly the same. The riddle is how can you know which bag has the nine gram marbles if the only device allowed to be used is a weighing scales which you can use only once?
Some day I'll be rich and famous for inventing a device that allows you to stab people in the face over the internet.
Damn, that 12 ball one is tough. I think I have it though.
Divide them up into 3 groups of 4. Call them Group A, B, and C.
Weigh Group A vs Group B.
Case 1: Group A = Group B.
In this case, you know the deviant ball is in group C. Weigh c1, c2 and c3 against a1, a2, and a3.
case 1.1: They are the same.
You know the deviant ball is c4. Weigh it against a1 to find out if it is light or heavy.
case 1.2: c1, c2 and c3 are heavier.
Weigh c1 vs c2. If they are the same, you know the ball is c3 and it is heavier. If they differ, you know that the heavier ball is the one.
case 1.3: c1, c2, and c3 are lighter.
Same as above. Weigh c1 vs c2. If they are the same, you know c3 is the light ball. If they differ, the ball that is lighter is the one you're after.
Case 2: A is heavier than B.
Take a1, a2, and b1, and weigh them against a3, b2, and c1.
case 2.1: a1, a2, and b1 are heavier.
Since you know the heavy ball must be in A or the light ball is in B, you can tell that the ball you want is either a1, a2, or b2. Weigh a1 vs a2.
case 2.1.1: They differ.
You know that the heavier ball is your ball.
case 2.1.2: They are the same.
You know that b2 is your ball and it is lighter.
Case 2.2: a1, a2, and b1 are lighter.
You know either b1 is your ball and it is lighter, or a3 is your ball and it is heavier. Weigh a3 vs c1.
case 2.2.1: a3 is heavier than c1.
You know a3 is your ball and it is heavy.
case 2.2.2: a3 is the same as c1.
You know b1 is your ball and it is lighter.
Case 2.3: a1, a2, and b1 are the same weight as a3, b2, and c1.
Basically, at this point, you have a4, b3, and b4 left. From your first measurement, you also know that a4 cannot be the lighter ball, nor can b3 nor b4 be the heavier ball. Take a4 and b3, and weigh them against c1 and c2.
case 2.3.1: a4 and b3 are heavier.
Since you know that b3 cannot be the heavier ball, a4 must be the ball you want, and it is heavy.
case 2.3.2: a4 and b3 are lighter.
Since you know that a4 cannot be the lighter ball, b3 must be the ball you want and it is lighter.
case 2.3.3: a4 and b3 are the same as c1 and c2.
You know that b4 is the deviant ball, and from your very first measurement, you know that it must be light.
Case 3: B is heavier than A:
Just repeat case 2 over, but switch all the balls labelled a for b.
DONE
Phew, that was hard.
Some day I'll be rich and famous for inventing a device that allows you to stab people in the face over the internet.
Well... am I right am I right????
Some day I'll be rich and famous for inventing a device that allows you to stab people in the face over the internet.
My hamster would just mollest your leg until you weighed each one!
<b>Cogposto tomsa, ergo sum - <i>Descartes</i>
</b>Translation:<b> I post at Toms Hardware, Therefor I am.
</b>
Okay, divide them into four groups A, B, C, D.
weigh (A, B);
if (A==B){
weigh (C, D); //they will be different
weigh (B, D)
if (B==D){
C = oddgroup; //you will now know if the variant / //is heavier or lighter based
/ //on whether C was heavier or / //lighter than D.
weigh (C1, C2);
if (C1==C2)
C3 = oddball;
elseif (C1 < C2)
C1 = oddball if C<D;
else
C2 = oddball;
I will not go to the detail of explaining what you would do if the variant is in a different group. It is basically the same procedure and I don't feel like semi coding the rest of it. I suppose recursion would be appropriate here, but that takes too much thought.
In a world without <font color=red>walls </font color=red>or <font color=green>fences </font color=green>, what use have we for <font color=red>Windows </font color=red>or <font color=green>Gates.</font color=green>
Ah!! it didn't format it correctly. Oh, well, it is still legible, but the indentation made it a lot easier to read.
In a world without <font color=red>walls </font color=red>or <font color=green>fences </font color=green>, what use have we for <font color=red>Windows </font color=red>or <font color=green>Gates.</font color=green>
That takes more than 3 tries.
Some day I'll be rich and famous for inventing a device that allows you to stab people in the face over the internet.
| Quote : Well... am I right am I right????
|
Sorry, I didnt get back to you earlier. I do need to sleep once in a while (bloody waste of time)
But yes. <b>RESPECT and WELL DONE !!!</b>
My solution differs slightly though. But its basically the same. Ill include it here, just for completion:
<pre>1) The first measurement always starts out with 4 balls on each side of the scale. Three
outcomes are possible:
1.1) Equal, all balls on the scale are normal and the deviating ball is among the
remaining 4. [Proceed with step 2.1]
1.2) Left side is heaviest. The deviating ball is among the eight on the scale, and the
remaining 4 are normal. But we also know that one of the balls on the left side is
heavier than normal OR one of the ball on the right side is lighter than normal. [Proceed
with step 2.2]
1.3) Right side is heaviest. The deviating ball is among the eight on the scale, and the
remaining 4 are normal. But we also know that one of the balls on the right side is
heavier than normal OR one of the ball on the left side is lighter than normal. [Proceed
with step 2.3]
</pre><p><pre>2) Second measurement
2.1) Put 3 normal balls one the left side, and 3 of the unknown on the right side. Three
outcomes are possible:
2.1.1) Equal. The selected 3 unknown are all normal, and the last unknown must be the
deviating. [Proceed with step 3.1]
2.1.2) Left side is heaviest. One of the 3 unknown is the deviating ball and it must be
lighter than normal. Further the last unknown ball must me normal. [Proceed with step
3.2]
2.1.3) Right side is heaviest. One of the 3 unknown is the deviating ball and it must be
heavier than normal. Further the last unknown ball must be normal. [Proceed with step
3.3]
2.2) We now have three groups: A) 4 normal balls. B) 4 balls where one of them may be
heavier. C) 4 balls where one of them may be lighter. Put 2 balls from B and 2 balls from
C on the left side. Put 2 balls from A, 1 ball from B and 1 from C on the right side.
Three outcomes are possible:
2.2.1) Equal. All balls on the scale are normal balls. We are left with two unknowns,
where 1 may be heavier and 1 may be lighter. [Proceed with step 3.4]
2.2.2) Left side heaviest. The two balls on the left side that could have been lighter
are now known to be normal. Further the 1 ball on the right side that could have been
heavier is now known to be normal. We are left with 3 unknowns, where 2 may be heavier
and 1 may be lighter [Proceed with step 3.5]
2.2.3) Right side heaviest. The two balls on the left side that could have been heavier
are now known to be normal. Further the 1 ball on the right side that could have been
lighter is now known to be normal. We are left with 3 unknowns, where 2 may be lighter
and 1 may be heavier [Proceed with step 3.6]
2.3) This is practically identical to 2.2, so i leave it out.
</pre><p><pre>3) Third measurement
3.1) The last deviating ball is measured against a normal ball to figure out whether is
lighter or heavier than normal.
3.2) We are left with three balls, and we know the deviating is lighter than normal. Put
one on each side of the scale. If equal the remain is the deviating, otherwise the scale
shows which is the lighter.
3.3) We are left with three balls, and we know the deviating is heavier than normal. Put
one on each side of the scale. If equal the remain is the deviating, otherwise the scale
shows which is the heavier.
3.4) Put the two unknown balls on the left side and two normal on the right side. If the
left side is heavier, the ball that could be lighter is normal and the other is the
deviating (heavier) one. If left side is lighter, the ball that could be heavier is
normal and the other is the deviating (lighter) one. This measurement cant turn out equal
since that would mean that all 12 balls are equal in weight.
3.5) Put one of the balls that may be heavier and the ball that may be lighter on the
left side. Put 2 normal balls on the right side. If equal the, all balls on the weight
are normal and the remaining unknown is the deviating (heavier) one. If not equal the
deviating ball is identified as in step 3.4
3.6) Put one of the balls that may be lighter and the ball that may be heavier on the
left side. Put 2 normal balls on the right side. If equal the, all balls on the weight
are normal and the remaining unknown is the deviating (lighter) one. If not equal the
deviating ball is identified as in step 3.4
</pre><p><pre>All this can be put in a graphical way, which may make more sense:
</pre><p><pre>Notation:
____|____ : The scale with some balls on the left and right side
Ball weight:
X: Unknown
-: Perhaps lighter than normal
+: Perhaps heavier than normal
H: Heavier than normal
L: Lighter than normal
O: Normal
Weigh result:
=: Left and right side are equal
/: Left side is heavier than right side
\: Left side is lighter than right side
!: All 12 balls are equal in weight (never occurs)
Initial condition:
abcdefghijkl
XXXXXXXXXXXX
1. weighing and result 2. weighing and result 3. weighing and result
abcd efgh abcdefghijkl abc ijk abcdefghijkl a l abcdefghijkl
XXXX|XXXX = OOOOOOOOXXXX OOO|XXX = OOOOOOOOOOOX O|X = OOOOOOOOOOOO <- !
/ OOOOOOOOOOOL
\ OOOOOOOOOOOH
i j abcdefghijkl
/ OOOOOOOO---O -|- = OOOOOOOOOOLO
/ OOOOOOOOOLOO
\ OOOOOOOOLOOO
i j abcdefghijkl
\ OOOOOOOO+++O +|+ = OOOOOOOOOOHO
/ OOOOOOOOOHOO
\ OOOOOOOOHOOO
abcdefghijkl aebf cgij abcdefghijkl dh kl abcdefghijkl
/ ++++----OOOO +-+-|+-OO = OOO+OOO-OOOO +-|OO = OOOOOOOOOOOO <- !
/ OOOHOOOOOOOO
\ OOOOOOOLOOOO
abcdefghijkl bg kl abcdefghijkl
/ ++OOOO-OOOOO +-|OO = HOOOOOOOOOOO
/ OHOOOOOOOOOO
\ OOOOOOLOOOOO
abcdefghijkl ce kl abcdefghijkl
\ OO+O--OOOOOO +-|OO = OOOOOLOOOOOO
/ OOHOOOOOOOOO
\ OOOOLOOOOOOO
abcdefghijkl aebf cgij abcdefghijkl dh kl abcdefghijkl
\ ----++++OOOO -+-+|-+OO = OOO-OOO+OOOO -+|OO = OOOOOOOOOOOO <- !
/ OOOLOOOOOOOO
\ OOOOOOOHOOOO
abcdefghijkl ce kl abcdefghijkl
/ OO-O++OOOOOO -+|OO = OOOOOHOOOOOO
/ OOOOHOOOOOOO
\ OOLOOOOOOOOO
abcdefghijkl bg kl abcdefghijkl
\ --OOOO+OOOOO -+|OO = LOOOOOOOOOOO
/ OOOOOOHOOOOO
\ OLOOOOOOOOOO</pre><p><i><b>"I don't understand what it is! Let me kill it!" -- Worf</b></i>
Regarding the marble exercise. Im not sure I understand what type of scale you mean. Is it a two-bowl balancing scale as in my riddle? In that case, I dont think its possible. However, if you actually can weigh (numerically) with the weigh, you do the following:
Put all bags on the weigh and note the total weight X. Solve the set of equations:
n*10+m*9=X
n+m=Total number of marbles
Find m. Since each bag has a unique number of marbles, you now which contains 9gr marbles.
<i><b>"I don't understand what it is! Let me kill it!" -- Worf</b></i>
<b>That's</b> why I couldn't solve it. I hate maths!
<b><font color=blue>~ <A HREF="http://www.btvillarin.com/phpBB/viewtopic.php?t=324" target="_new">My System Specs</A> ~<font color=blue></b>
Yeah, it's a numerical scale, not a balance
Some day I'll be rich and famous for inventing a device that allows you to stab people in the face over the internet.
I just went over your solution very quickly (have to go to work soon), but it seems as though our solutions are exactly the same, with the exception of formatting. The actual method is the same though
Some day I'll be rich and famous for inventing a device that allows you to stab people in the face over the internet.
oops, I must of got so caught up writing it like code that I forgot to count the number of weighs I used.
In a world without <font color=red>walls </font color=red>or <font color=green>fences </font color=green>, what use have we for <font color=red>Windows </font color=red>or <font color=green>Gates.</font color=green>
All these riddles are driving me crazy. I have VACATION... so I don't want to think to much.
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We need some more riddles here.
Some day I'll be rich and famous for inventing a device that allows you to stab people in the face over the internet.
NO... please NO!
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Yeah we need some more intelligent discussion going on here...
Some day I'll be rich and famous for inventing a device that allows you to stab people in the face over the internet.
I'm up for that. I feel like i get dumber everyday.
What good fortune for those in power that people
do not think. - <b>Adolf Hitler</b>
I think your IQ and your post count have an inverse relationship. That's why I can't even remember my address any more
Wingding - Santa's nightmarish alter ego
lol.. good way to put it.
Hey does anyone here play Red Alert 2 Yuri's revenge? Wanna go at it in an online game.
What good fortune for those in power that people
do not think. - <b>Adolf Hitler</b>
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