On the shelf you have 10 identical bottles of identical
pills (let?s say there?s a hundred pills in each bottle).
However, one of those 10 bottles contains cheap knockoff
pills. The only way to differentiate fake pills from real
pills is the weight - while real pills weigh 1 g each, the
knockoff pills are only 0.9 g. You have one scale that
shows the exact weight (down to the mg) of whatever is
weighed.

How can you tell which bottle contains fake pills with just
1 weighing?

Answers were Sorted based on User's Feedback



On the shelf you have 10 identical bottles of identical pills (let?s say there?s a hundred pills i..

Answer / anil

>pick 1 pill from bottle1,2 from bottle2,3 from bottle3 and
so on.
>calculate the weight using the weighing scale.
>now,if all were real the total weight would have been
1+2+3+....+10=55g
>but here there is one bottle with fake pills.
>therefore,
if the total weight=[55-(0.9)*(1)],bottle1 contains fake
pills.
if the total weight=[55-(0.9)*(2)],bottle2 contains fake
pills.
if the total weight=[55-(0.9)*(3)],bottle3 contains fake
pills.
........and so on.
>in this way we can find the bottle containing fake pills.

Is This Answer Correct ?    41 Yes 7 No

On the shelf you have 10 identical bottles of identical pills (let?s say there?s a hundred pills i..

Answer / khanij kumar s g

First arrange the 10 bottels one after the other,take 1
pill, 2pills, 3pills,.... from the first, second,third,....
bottels respectively

Then there are (10)(11)/2=55 pills with you
if each wieghs 1g, then 55 pills must wiegh 55g,
if the first bottle contains the knockoff pill then the 55
pills would have weighed 54.9 g
if the 2 nd bottle contains knockoff pills, then the weight
would be 54.8g
similarly you can tell the bottel which contains the
knocked pills with the following formula,
if the difference in weight is 'x'g then '10x' th bottel
contains the knocked pills

Is This Answer Correct ?    31 Yes 2 No

On the shelf you have 10 identical bottles of identical pills (let?s say there?s a hundred pills i..

Answer / appu

First arrange the 10 bottels one after the other,take 1
pill, 2pills, 3pills,.... from the first, second,third,....
bottels respectively

Then there are (10)(11)/2=55 pills with you
if each wieghs 1g, then 55 pills must wiegh 55g,
if the first bottle contains the knockoff pill then the 55
pills would have weighed 54.9 g
if the 2 nd bottle contains knockoff pills, then the weight
would be 54.8g
similarly you can tell the bottel which contains the
knocked pills with the following formula,
if the difference in weight is 'x'g then '10x' th bottel
contains the knocked pills

Is This Answer Correct ?    9 Yes 0 No

On the shelf you have 10 identical bottles of identical pills (let?s say there?s a hundred pills i..

Answer / santhi priya

First arrange the 10 bottels one after the other,take 1
pill, 2pills, 3pills,.... from the first, second,third,....
bottels respectively

Then there are (10)(11)/2=55 pills with you
if each wieghs 1g, then 55 pills must wiegh 55g,
if the first bottle contains the knockoff pill then the 55
pills would have weighed 54.9 g
if the 2 nd bottle contains knockoff pills, then the weight
would be 54.8g
similarly you can tell the bottel which contains the
knocked pills with the following formula,
if the difference in weight is 'x'g then '10x' th bottel
contains the knocked pills

Is This Answer Correct ?    6 Yes 0 No

On the shelf you have 10 identical bottles of identical pills (let?s say there?s a hundred pills i..

Answer / rosie adams

Why weigh you can quickly scan the bottle using EDXRD
technology and get a pass/fail answer. It sees through the
packaging and compares the molecular structure of the sample
to its standard to verify the authenticity and quality of
the sample.

Weighing is no longer a valid method of differentiating the
fake from the real.

For more information on EDXRD technology, visit
http://www.xstreamsystems.net/technology.html

Is This Answer Correct ?    2 Yes 11 No

On the shelf you have 10 identical bottles of identical pills (let?s say there?s a hundred pills i..

Answer / ilakya

first name the bottles and keep all the bottles on the
scale so that it makes the sum of all the bottles if one is
less u could find out which one by its name

Is This Answer Correct ?    1 Yes 16 No

On the shelf you have 10 identical bottles of identical pills (let?s say there?s a hundred pills i..

Answer / xyz

put all 10 bottles in weighing machine.then total weight is
10*100*1-0.9*100=990. (note:neglect bottle weight since
bottle is not specified)
Then take any one bottle from weighing machine ,and see
if it shows 890 it is not fake.if it shows 900 then it is
fake.(since weight of fake bottlt is 90gm.)....

Is This Answer Correct ?    3 Yes 20 No

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