Guest Posted May 26, 2008 Report Share Posted May 26, 2008 I tried searching it, but nothing came up.. so here goes there are twelve balls all of them are of equal weight, except for one, which is a bit heavier than the rest. They all have the same appearance so it's impossible to tell by looking. You have one balance (the one that has two platforms at each end used to measure which object weighs more..Not the one showing you the numerical values) Using this balance, you have to figure out which ball is the heavier one. Can you find the ball within three tries (using the balance three times)? (you have to list all the possible scenarios) Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 26, 2008 Report Share Posted May 26, 2008 Split into two groups of 6, take the heavier group and split it into two groups of three. Take the heavier group of three and measure two balls from it. If they balance, the third ball is heavier, if one of them weigh down the scale, it's the heavier one. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 26, 2008 Report Share Posted May 26, 2008 (edited) It's a good one, but yeah, it has been done before. Edit: Actually, as shown in the other post, you can find the odd ball in three times even if you don't know if it's heavier or lighter, which is considerably more tricky. Edited May 26, 2008 by Duh Puck Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 26, 2008 Report Share Posted May 26, 2008 divide the balls into 3 groups of 4. weight two of the groups. If one group is heavier, discard the other two groups. If both groups weigh the same, discard them both (because the heavier ball is obviously in the third, unwieghed group.) Divide the chosen group into twos and weigh. Using the two that wiegh heaviest, weigh them against one another...you'll find the heaviest ball. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 26, 2008 Report Share Posted May 26, 2008 OH! Oops ya sry dat's wut I meant to say one of the balls has a different weight (not necessarily heavier- could be lighter) and sry for repeating... arrg, should hav looked for the old one more carefully... Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 26, 2008 Report Share Posted May 26, 2008 OH! Oops ya sry dat's wut I meant to say one of the balls has a different weight (not necessarily heavier- could be lighter) and sry for repeating... arrg, should hav looked for the old one more carefully... No worries. It actually took me a few searches to find it, and I only found it because I knew it was there. Quote Link to comment Share on other sites More sharing options...
0 rookie1ja Posted May 26, 2008 Report Share Posted May 26, 2008 actually, the search was quite easy ... keywords used were "twelve +balls" thread locked Quote Link to comment Share on other sites More sharing options...
Question
Guest
I tried searching it, but nothing came up.. so here goes
there are twelve balls
all of them are of equal weight, except for one, which is a bit heavier than the rest.
They all have the same appearance so it's impossible to tell by looking.
You have one balance (the one that has two platforms at each end
used to measure which object weighs more..Not the one showing you the numerical values)
Using this balance, you have to figure out which ball is the heavier one.
Can you find the ball within three tries (using the balance three times)?
(you have to list all the possible scenarios)
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