Weighing VII.

[Guest]

Now that everyone has tried this puzzle and seen the answer, let's try it with a little twist:

What if you didn't know if the one ball that weighed different was heavier or lighter? Then how many times on the scales would it take?

If I'm not mistaken it will only take 4. The first time the scale registers a difference between two groups you will have to weigh one of those two groups one more time against the third group. This will let you know which group is different and if it is heavier or lighter. The rest of the puzzle is exactly the same.

[rookie1ja]

Now that everyone has tried this puzzle and seen the answer, let's try it with a little twist:

What if you didn't know if the one ball that weighed different was heavier or lighter? Then how many times on the scales would it take?

If I'm not mistaken it will only take 4. The first time the scale registers a difference between two groups you will have to weigh one of those two groups one more time against the third group. This will let you know which group is different and if it is heavier or lighter. The rest of the puzzle is exactly the same.

the variation is already posted with good discussion ... check this

I have dedicated one whole page to such Weighing Puzzles

[Guest]

9 9 9 is my first choice.. if somene is interested in alternative answer here u go.. (but it takes 6 times)

14 13

take 1 ball from any 14 (lhs)

if you take the heavier ball by first chance from lhs, scale equals

if not ,remove the first ball taken aside

13 13 (assuming that normal ball is taken, the heavier side will slide as both sides are having equal balls)

7 6

if you take the heavier ball by chance from lhs, scale equals

if not, remove the ball taken aside..so

6 6

now look which side is heavier..n split those in to two halves

3 3

now look which side is heavier

2 1

now remove one ball from lhs n see if it equals..

1 1

if the heavier ball is still left out, it slides and thats it .

[Guest]

Heres how I would of solved it.

First you split the groups to three groups, 13, 13, 1.

Second Weigh the two Thirteen groups to eachother, Should one be heavier you eliminated most of them, Should they be the same then the last ball you have is the heavier one.

If second step does not work then sepereate the balls again into three groups, 6, 6, 1.

Weigh them again following step 2

Weigh the heavier side, 3, 3.

Weigh the heavier side, 1, 1, 1.