Interested to Buy Any Domain ? << Click Here >> for more details...
You have 13 balls which all look identical. All the balls
are the same weight except for one. Using only a balance
scale, can find the odd one out with only 3 weighings?
Is it possible to always tell if the odd one out is heavier
or lighter than the other balls?
- 9 Answers
- 40274 Views
- Sapient, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / guest
It is always possible to find odd ball in 3 weighings and in
most of the cases it is possible to tell whether the odd
ball is heavier or lighter. Only in one case, it is not
possible to tell the odd ball is whether heavier or lighter.
1. Take 8 balls and weigh 4 against 4.
o If both are not equal, goto step 2
o If both are equal, goto step 3
2. One of these 8 balls is the odd one. Name the balls on
heavier side of the scale as H1, H2, H3 and H4. Similarly,
name the balls on the lighter side of the scale as L1, L2,
L3 and L4. Either one of H's is heavier or one of L's is
lighter. Weigh (H1, H2, L1) against (H3, H4, X) where X is
one ball from the remaining 5 balls in intial weighing.
o If both are equal, one of L2, L3, L4 is lighter. Weigh L2
against L3.
? If both are equal, L4 is the odd ball and is lighter.
? If L2 is light, L2 is the odd ball and is lighter.
? If L3 is light, L3 is the odd ball and is lighter.
o If (H1, H2, L1) is heavier side on the scale, either H1 or
H2 is heavier. Weight H1 against H2
? If both are equal, there is some error.
? If H1 is heavy, H1 is the odd ball and is heavier.
? If H2 is heavy, H2 is the odd ball and is heavier.
o If (H3, H4, X) is heavier side on the scale, either H3 or
H4 is heavier or L1 is lighter. Weight H3 against H4
? If both are equal, L1 is the odd ball and is lighter.
? If H3 is heavy, H3 is the odd ball and is heavier.
? If H4 is heavy, H4 is the odd ball and is heavier.
3. One of the remaining 5 balls is the odd one. Name the
balls as C1, C2, C3, C4, C5. Weight (C1, C2, C3) against
(X1, X2, X3) where X1, X2, X3 are any three balls from the
first weighing of 8 balls.
o If both are equal, one of remaining 2 balls is the odd
i.e. either C4 or C5. Weigh C4 with X1
? If both are equal, C5 is the odd ball. But you can not
tell whether it is heavier or lighter.
? If C4 is heavy, C4 is the odd ball and is heavier.
? If C4 is light, C4 is the odd ball and is lighter.
o If (C1, C2, C3) is heavier side, one of C1, C2, C3 is the
odd ball and is heavier. Weigh C1 and C2.
? If both are equal, C3 is the odd ball and is heavier.
? If C1 is heavy, C1 is the odd ball and is heavier.
? If C2 is heavy, C2 is the odd ball and is heavier.
o If (C1, C2, C3) is lighter side, one of C1, C2, C3 is the
odd ball and is lighter. Weigh C1 and C2.
? If both are equal, C3 is the odd ball and is heavier.
? If C1 is light, C1 is the odd ball and is lighter.
? If C2 is light, C2 is the odd ball and is lighter.
| Is This Answer Correct ? | 49 Yes | 10 No |
Answer / rahul khanduri
Little difficult, I found the soln then I forgot, and I am too lazy to right it here, so basically you have to use little brain, you have to think that if one side is heavy this can't be because of this and that, I think op got my ans.
| Is This Answer Correct ? | 0 Yes | 2 No |
Answer / atul saxena
Yes it is always possible to tell if the odd ball is heavier or lighter than the other balls with only three weighings.
| Is This Answer Correct ? | 1 Yes | 5 No |
Devide these 13 balls into 3 categories i.e 6,6,1. Then measure both 6 and 6 . You will find the result. If both are equal then off one is the left out ball. If not equal then make another separate to the less weight 6 ball into 3 and 3. Same way measure these 3 and 3 . Find out the less weight side. Again separate this three into 1,1,1. Then measure any 2. You will find the needed result.
| Is This Answer Correct ? | 2 Yes | 6 No |
Answer / kamran khan
13 balls are divide into four group (3,3,3,3,1)
1)First measure one pare of (3,3) . If it is equal then measure an other part
if it is also equal then last one is defective .
you suppose to first measure is unequal then unequal portion take and pick up on ball i.e(measure 1,1) and one is taken out if both are same then taken out ball is defective otherwise between two any one is defective
| Is This Answer Correct ? | 1 Yes | 8 No |
Answer / vinay tyagi
first of all it is necessary that we must know that
the odd ball is heavy or light than others.
Ans. suppose odd ball is heavy.
divide balls among three group abruptly
I 6 balls
II 6 balls
III 1 ball
now measure group I against II
1. if equal then odd ball is III grop
2 if not equal then odd ball is in heavier side
3. now from the heavier side 6 ball , just divide them into
two groups of 3 ball each
4. measure these groups and find the heavier one
5 now we have 3 ball , just choose two balls and measure
against each other, we can find the heavier one if found equal then third ball is the odd one
| Is This Answer Correct ? | 5 Yes | 13 No |
Answer / mohit kaushik
divide 13 in 4(I) , 4(II) , 4(III) , 1
1.) weigh I against II if equal
2.) weigh I against III if equal , the ball left is defective.
after performing step 1. and 2. in either of the step the
scale is not balanced.
Suppose it is not balanced in case 1 .( You can consider
case 2. if u like )
took any two balls from case 1 & weigh against each other.
if equal defective ball must be in group of other two.
take any ball from other group if scale is equal the ball
left is defective or else the chosen ball from the group of
two is defective.
By : mohit
Provide feedback
| Is This Answer Correct ? | 6 Yes | 16 No |
Answer / nitin verma
The question is incomplete
at least one of the thirteen balls should be given as known correct weighing ball separately.
Then only it can be solved correctly.
And it is actually much more difficult than it look to be.
And there is only one way to start I.e keeping 5 balls on both sides with one known ball on any side and rest 3 aside.
Your question is incomplete or wrong
| Is This Answer Correct ? | 2 Yes | 12 No |
Answer / nitin phunsukh wangru verma
How simple
you guys are such a JACK ASS
read the question carefully
the right answer is
No it not possible to catch the faulty ball all the time with exact fault I.e light or heavy
but it is a good question and can be asked in a better way
as I said earlier.
| Is This Answer Correct ? | 2 Yes | 17 No |
A group of friends went on a holiday to a hill station. It rained for 13 days. But when it rained in the morning, the afternoon was lovely. And when it rained in the afternoon, the day was preceded by clear morning. Altogether there were 11 very nice mornings and 12 very nice afternoons. How many days did their holiday last?
can you work well under deadlines or pressure?
1 Answers Academy Of Aerospace Aviation, Qatar Airlines,
A cube is made of a white material, but the exterior is painted black. If the cube is cut into 125 smaller cubes of exactly the same size, how many of the cubes will have atleast 2 of their sides painted black?
greatest achievement in life
iwant to know which type of questions were coming in tcs company
In the General meeting of "Friends Club", Sameer said, "The repairs to the Club will come to a total of Rs 3120 and I propose that this amount should be met by the members, each paying an equal amount." The proposal was immediately agreed. However, four members of the Club chose to resign, leaving the remaining members to pay an extra Rs 26 each. How many members did the Club originally have?
how would u find d exact number of white maruti cars in mumbai???
15 Answers Bhel, Infosys, RR, TCS,
How many such pairs of letters are there in the word TERMINATE each of which has as many letters between them in the word as in the English alphabet ?
You are in a boat with your mother and wife. Suddenly you are forced to drop somebody into water due to boat overloading. You cannot drop yourself. Whom will you drop?
A boy found that he had a 48 inch strip of paper. He could cut an inch off every second. How long would it take for him to cut 48 pieces? He can not fold the strip and also, can not stack two or more strips and cut them together.
Classic: If a bear walks one mile south, turns left and walks one mile to the east and then turns left again and walks one mile north and arrives at its original position, what is the color of the bear
16 Answers ADP, Microsoft, OSI, TCS, Tech Mahindra,
If a rook and a bishop of a standard chess set are randomly placed on a chessboard, what is the probability that one is attacking the other? Note that both are different colored pieces.
English 
