I have a tricky question for all

Here goes the question:

There are 9 ball.
8 balls are of same weight but one is a little lighter in weight.

You are given a balance which you can use only 2 times. (only the balance, not any standard weight)
You have to pick the ball which is lighter in weight.

How CAN you Answer this???????

Give a try, I am waiting for some answers

 

first of all, take 8 balls. 4 one side, another 4 on other side. if they're same weighted, remaining ball is lighter. if one side comes up, take 4 balls from there and measure with 2 balls each side. one side will come up. measure again. now you've got the lighter one.

shoooooo! such a big answer!

 

Pick any 2 balls and compare these against each other, e.g. {1} against {2}. If the scale balances, you know it is ball 3 is the heavier.

WRONG. Ball 3 could be heavier than either ball 1 or ball 2, but NOT heavier than ball 1 and 2 combined. This quiz is flawed.

I don't know what i am trying to say. its weird

- Digital -

 

I told you can use the balance only twice, not thricev

 

Keep trying, When I will say the answer you alll will have the same expression "SO SIMPLE"

 

ok, then take 6 balls. 3 one side and other 3 another side. if they are same weighted, you can get the lighter one using another only one measure from remaining 3 balls. If one side comes up, then measure 2 out of three. Now you got the lighter one .

Good tricky question!

 

GREAT man, you did it. You really have that thing called "Grey Matter"

 

Thanx mate! The question was nice. Now I've another good collection .

 

Next tricky question: http://forums.digitalpoint.com/showthread.php?p=11411952#post11411952

 

Nice Tricks n awesome solution...

 

intelligent trick and the right answer...Cheers

 

But what happens if the first 6 balls are not the same weight?

 

You select the two from the ones showing lighter weight and balance them. If they both show to be equal, the remaining one is lighter or else the scale would simply give you the lighter one!

Wow...congrats, Suman...for solving the puzzle so quickly, and for having a lot of gray matter.
Please do not use this gray matter for gray-hat technique though!

Regards,

RightMan

 

Well...thanx RightMan! To say...I love most the green matter . Anyway, hope no objection to implement green-hat technique .

 

yes nice question and nice solution.........

 

lol... I wouldn't solve this if I didn't read it

maybe I'm just dumb hehe

 

No way you said i can use the balance only twice?. ups..

 

Ya man. Divide the 9 balls in 3 groups (3 balls each)
First take 2 groups and balance. if one side goes down then you know that the other side has the lighter ball, if both weigh same then the 3rd group will have the ball with lighter weight.[Till now you have used the balance only once].

Since by now you know which of the three group(having 3 balls each) has the light weighed ball you can now easily select any 2 of the 3 balls and weigh them, if they weigh same then the 3rd left-over ball is the light weighed one, and if one side of the balance goes down then the light weighed ball is one the other side. [Now you have used the balance for second time and got the ball with light weight]

Now is it OK?