Puzzle: 8 balls of same size

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If u have 8 balls of all the same size and 7 of them weigh the same, and one of them weighs slightly more. How can you find the ball that is heavier by using a balance and only two weighings?

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By  Shiva kumar





Roshan Singh Roshan Singh   11 years ago

Steps:
1> make three sets :
B: 2 balls
C: 3 balls
D: 3 balls
2> weigh C and D against each other.
If C = D then the heavier ball belongs to B:
jump to step 3.
else
jump to step 5.
3> weigh both balls of B against each other to find out the heavier ball.Done.
4> take the heavier set out of C and D and then take any two balls out of that set and weigh them against each other to find the heavier one. If both are equal in weight then the 3rd ball is the heavier one. Done.

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Rohit Singhal Rohit Singhal   11 years ago

First time weigh 3-3 balls.
If they are equal then weigh remaining two balls and which one would be heavier among those two that would be your answer.
If they are not equal then consider three balls which are heavier for next weigh.
Now from these three balls weigh 1-1 balls. If they are equal then remaining third ball is your answer otherwise if they are not equal then whichever is heavier is your answer.

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