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Question: There are 12 balls looks identically equal. But one of them has weight different(more or less) from other. How to find that dissimilar ball with minimum balances?

Answer: Three Balances
Divide in 3 equal parts (4 balls). Weight two parts if both are equal then pick third part divide in 2 parts (2 balls). Pick the heavy side and weight.



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Question: There are 12 balls looks identically equal. But one of them has weight different(more or less) from other. How to find that dissimilar ball with minimum balances?
Answer:

Three Balances
Divide in 3 equal parts (4 balls). Weight two parts if both are equal then pick third part divide in 2 parts (2 balls). Pick the heavy side and weight. Source: CoolInterview.com

Answered by: anmol | Date: 5/24/2008 | Contact anmol Contact anmol

If you see the question.. "weight different(more or less)"

The weight is not known, whether it is less or more..

So the above mentioned solution is not perfect. Source: CoolInterview.com

Answered by: Jitendra | Date: 6/16/2008 | Contact Jitendra Contact Jitendra

Firstly divide the 12balls into three groups of 4balls numbered 1,2,3

Weigh group1(g1) against group2(g2), g2 vs g3, g3 vs g1.

One of these would be equal. Note that the other group will have the ball we are in search of. Suppose take it as g2.

Now take a ball from either g1 or g3 and weigh the 4balls against g2.

Now, which ever weighs more or less than the ball from g1 or g2. Source: CoolInterview.com

Answered by: Bhavya Shree S | Date: 6/23/2008 | Contact Bhavya Shree S Contact Bhavya Shree S

Firstly divide the 12balls into three groups of 4balls numbered 1,2,3

Weigh group1(g1) against group2(g2), g2 vs g3, g3 vs g1.

One of these would be equal. Note that the other group will have the ball we are in search of. Suppose take it as g2.

Now take a ball from either g1 or g3 and weigh the 4balls against g2.

Now, which ever weighs more or less than the ball from g1 or g2.

So totally it is 3+4= 7balances Source: CoolInterview.com

Answered by: Bhavya Shree S | Date: 6/23/2008 | Contact Bhavya Shree S Contact Bhavya Shree S

Three Steps:

we don't know the different weight is more or less so.. divide into Four equal parts (3-3-3-3)

part-1,Part-2,part-3 ,Part-4

Step 1: Take part 1 and 2 check,

if both equal take any one part
Step 2: compare with part-3 if it's equal then Part 4 having the different weight ball. not equal then part 3 having the different weight ball.

if both are not equal take part2
Step 2: compare with part-3 if it's equal then Part 1 having the different weight ball. not equal then part 2 having the different weight ball.

(Checking this itself we can identify the different ball weight is more or less)

step 3:It having 3 ball's take any two check it both equal the other one ball is different or based on the condition its less means the lesser one is different or greater one.
Source: CoolInterview.com

Answered by: Lijo | Date: 6/23/2008 | Contact Lijo Contact Lijo

Three Steps:

we don't know the different weight is more or less so.. divide into Four equal parts (3-3-3-3)

part-1,Part-2,part-3 ,Part-4

Step 1: Take part 1 and 2 check,

if both equal take any one part
Step 2: compare with part-3 if it's equal then Part 4 having the different weight ball. not equal then part 3 having the different weight ball.

if both are not equal take part2
Step 2: compare with part-3 if it's equal then Part 1 having the different weight ball. not equal then part 2 having the different weight ball.

(Checking this itself we can identify the different ball weight is more or less)

step 3:It having 3 ball's take any two check it both equal the other one ball is different or based on the condition its less means the lesser one is different or greater one.
Source: CoolInterview.com

Answered by: lijo | Date: 6/23/2008 | Contact lijo Contact lijo

take 3 sets of 4 balls each.
balance number 1( BN 1) : balance any two, if its equal then take the third one for further experimenting otherwise if not equal then BN 2 compare any one with the third one.. you will get to know the odd set

now we have 4 balls knowing that one of them is odd..
so naming them as a,b,c,d... ok

BN3: balance a & b,
if a=b , then BN 4 : balance a with c, if a=c then ball D has the odd weight. and if a is not = to c, then C is the odd one.

if a is not equal to b, BN 4: balance a with c, if a=c then B is the odd one, otherwise if a is not = to c, then A is the odd one...

i hope my language is understandable... :)
thank you.. Source: CoolInterview.com

Answered by: abhinav srivastava | Date: 6/23/2008 | Contact abhinav srivastava Contact abhinav srivastava

12
/
/
6 6(less wt out)case:1
/
/
3(1 ball kept other side)
2
case 2:
/
/
1 1
2 case arise
case 3:
1) both equal then kept is dissimilar
2)wted ball unequal
then 1 of the ball dissimilar
hence in 3 step we know our ans.... Source: CoolInterview.com

Answered by: bikash | Date: 6/27/2008 | Contact bikash Contact bikash

Three Balances
Divide in 3 equal parts (4 balls). Weight two parts if both are equal then pick third part divide in 2 parts (2 balls). Pick the heavy side and weight.
Source: CoolInterview.com

Answered by: satheeshkumar.J | Date: 7/1/2008 | Contact satheeshkumar.J Contact satheeshkumar.J

Divide in to two 6 balls and 6 balls in your both hand

the difference again divide into 2
both hand 3 and 3

the difference again divide 3 and put 1 more from previous

and then divide in to two 2 & 2

difference and find
Source: CoolInterview.com

Answered by: muhammad javed iqbal | Date: 7/4/2008 | Contact muhammad javed iqbal Contact muhammad javed iqbal

DIVIDE IN TO FOUR GROUPS OF 3 BALLS EACH.
WEIGH THREE GROUPS. IF ALL WEIGHTS ARE EQUAL SEPERATE THE FOURTH. ELSE, ANY ONE GROUP DIFFERS WITH OTHER TWO SEPERATE THAT. NOW YOU BALANCED THRICE. TAKE THE SEPERATED ONE WHICH CONTAIN THREE BALLS. WEIGH THE BALLS BY KEEPING ONE IN LEFT AND ANOTHER IN RIGHT. IF ANY DIFFERENCE FOUND YOU CAN POINT OUT THE DIFFERENT BALL. OTHERWISE THE OTHER BALL IN YOUR HAND IS THE BALL WITH DIFFERENT WEIGHT. SO YOU WEIGHED ONLY FOUR TIMES. Source: CoolInterview.com

Answered by: L J RAJAGOPALAN. | Date: 7/11/2008 | Contact L J RAJAGOPALAN. Contact L J RAJAGOPALAN.

Split the balls into 5,5,2

first trial:

weigh 5 and 5.. if equal.. compare the rest of the two balls and find the odd one..

second method:

weigh 5 and 5.. if unequal..take the unequal 5 and split it into 2,2,1...

now weigh 2 and 2.. if equal .. then remaining 1 is the odd one..

if not weigh the unequal 2 and find the odd one Source: CoolInterview.com

Answered by: thangaraj | Date: 8/22/2008 | Contact thangaraj Contact thangaraj

Only three trails. First i'll take a balance and i'll place 6 balls on each side.since 1 ball has different weight from others, its easy to recognize which side that ball is. In second step, i'll take those 6 balls and place them 3 in each side. Next i'll take 2 balls out of those 3 balls and i'll place them in the balance, if the balls show the same weight, then the third one is the actual ball with different weight. If the weight of the two balls is not same, then the actual ball is found in the balance. Source: CoolInterview.com

Answered by: Joselyn | Date: 10/7/2008 | Contact Joselyn Contact Joselyn

3 Times
1st Time: Divide 6-6 weight it some of the 6 or less wait
2nd Time:Take those less weightt 6 balls(In this 6 balls 1 of the ball is less wait).divide those 6 balls to 3 - 3and weight it.It will give 3 balls(some of the 3 balls are weight less)
do the same thing in 3rd time. Source: CoolInterview.com

Answered by: Samba Shiva Reddy | Date: 2/8/2010 | Contact Samba Shiva Reddy Contact Samba Shiva Reddy

Divide into a,b,c,d contains 3 each
weigh a Vs b and a Vs c.
If a=b and a=c then consider d
If a=b and a<>c then consider c
If a<>b and a=c then consider b
If a<>b and a<>c then consider a
now take the considered set and name each ball as p, q, r
weigh p Vs q and p Vs r.
If p=q and p<>r then r is required one
If p<>q and p=r then q is the required one
If p<>q and p<>r then p is the required one
In this method we use the balance 4 times
Source: CoolInterview.com

Answered by: Mohankumar | Date: 5/4/2010 | Contact Mohankumar Contact Mohankumar

divide into 4groups with 3 on each.
weigh g1 vs g2.
if g1=g2,
wt g1 vs g3;
if eual again g4 has odd ball
if g1!= g3,
g3 has odd ball.
else if g1!=g2,
wt g1 vs g3,
if g1=g3, g2 has odd ball
else g1 has it

In two weighing we got the group with odd ball.

In this two weighing we know that the defective ball is heavier or lighter.

once we get the odd balls group, we can take any two from three and wt againts each other if equal, 3rd one is defective and if different, one one with light or heavy wt,as we had find before
Source: CoolInterview.com

Answered by: krishnaa | Date: 5/18/2010 | Contact krishnaa Contact krishnaa

Only 3 balance is enough to identifying dissimilar one ,out of 12 balls
Step-1:-Frist of all ,,,12 will be divided into 2 groups(6/6)
Balanced, which is greater group(6),take that group,
Step-2:- And again divided into 2 groups(like3/3)? ,
Once again balanced it , take greater group(3),
Step-3:-On that group (3balls) take 2 balls out of 3 balls, (1/1 )balanced ,if both r equal,remain ball is dissimilar .otherwise dissimilar one is on that balance ?..
Source: CoolInterview.com

Answered by: sivaiah | Date: 5/21/2010 | Contact sivaiah Contact sivaiah

Hi guys....
All Ans are wrong!
Please note that the ball is unknown.
You have to find the difference ball and also you should able to tell whether weight high or less.

All answers wrong! Source: CoolInterview.com

Answered by: Naga Bhushanam Varikuti | Date: 7/10/2010 | Contact Naga Bhushanam Varikuti Contact Naga Bhushanam Varikuti


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