I have a logic puzzle I can't figure out. Help?

[Happy Girl=)]

Okay, I have thought about this until it made my head hurt. So, the person that gives me the right / (if nobody gets it) most plausible answer will get the points. I have an idea i think is pretty close, but I don't want to post it because I don't want to cloud your thoughts with my idea. Given are 12 marbles. One of these marbles is slightly heavier or lighter than the others. You have a two plate scale. You are allowed to weigh three times.Can you find the marble that differs in weight?So even if you have just a starter idea of what might work then tell me! Thanks =)Wonder, I had the same idea at first. I was really happy because I thought I figured it out. However, then I hit a wall when I read the question again. If you look you will notice the different marble may be heavier or lighter. So how do you eliminate both?The Bob, I think you are quite incorrect. Things don't necessarily weigh a certain amount because of their size, it is the density that matters. Good try! =)Patrick, if we knew if the differing marble was heavier or lighter there wouldn’t be much of a problem, would there?Hotelmoj… and Jsmprl I think you have it! Congrats =) Sadly I can’t give the points to FinkyFen... now. He made me laugh.

[Zelda Freak]

to hard to answer dont get it byeeeeeeee

[Wonder]

First weigh 6 on each scaleSave the one's that are heavierThen put 3 on each scaleSave the one's that are heavierThen weigh 1 on each scale.If one is heavier, you've found it. If neither are heavier, the leftover is.-MM

[FinkyFeke]

Put six on each; one will be heavier. Put three on each from the heavier side. Again one side will be heavier. Take the three from the heavier side.Take two of these at random. Place them on the scales. If one is heavier, that's the marble. If they're the same, it's the other one.Pick me, not Wonder, his grammar is bad...

[The Bob]

Look for the larger or smaller marble and save the weighing. The only way it would weigh more or weigh less is if the size is different.

[Macho-man]

Well, if it's slighty heavier OR lighter than that will throw off my whole answer. But here goes. First, weigh 6 marbles on each side. If you're looking for the heavier marble, then you know it's on the side that weighs the most. So split those 6 to weigh 3 on each side, and again determine the heaviest pile. With the remaining 3, weigh 1 against 1, and set the 3rd one aside. If the two you chose to weigh weigh the same, then heavier marble is the one you set aside. If one is heavier, then obviously that one would be the marble. And this whole things works same if you're looking for the lighter marble. But I have no idea how to do it looking for an unknown either heavier or lighter. If you have the answer, let me know after this question's over how to do it. =)

[Monica]

6-6-the one thats heavier or lighter goes3-3 to this one, same thing2-1same thinglol. idk just a guess.

[daveymc0926]

take the marbles and put them in three sets of 4. put one set on each of the two plates. if they weigh the same then the one set left out will be the one with the lighter marble. if one on the scale weighs more, then that will be it so with one measurement you have narrowed it down to 1 set of 4. split that in half and put 2 marbles on each plate take the lighter set of 2 sand split them and put them on the 2 plates. 3 measurements one marble left GIVE ME THE POINTS!

[daweaves68]

I would agree with wonder except for one problem. The question states that one marble is slightly heavier OR lighter. If it's lighter you eliminated it on the first weighing. The three vs. three weight would then be equal and you need 4 weighings to figure it out.daveymc's answer still doesn't work if different one is heavier, but better.I didn't have time to analyze it completely, but I think George has it. Thanks, it was driving me crazy.

[Patrick P]

I don't have enough info to figure this out yet. I need to know if the differing marble is heavier or lighter.

[hotelmajor]

divide the marbles into 3 groups of 4 place group 1 on one side of the scale and group 2 on the other (if they are equal then those 2 groups are out) if they are not equal then place the lighter group to the side and place group 3 on the scale (if they are equal then these 2 groups are out) take the last group and place them 2 and 2 on the scale, then go down to 1 and 1.That is my thought process, I have no idea if it is the right answer or not!Good luck!!