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Wed 3 Dec, 2003 01:27 pm
In front of you there are 11 bags with coins, all containing 10 coins. One bag has false coins. The false coins weigh 11 grams each, and the normal coins 10. You can only weigh one bag to get the false coins. What do you do?
Just take all the money...=P
Weigh one bag, and if it's not right, empty out the other bags and weigh the coins that were in them.
Then take the money.
You can only weigh one bag, no futher weighing is allowed.
Label the 11 bags A through K
Take no coin from A, 1 from B (marking it "B"), 2 from C (marking them "C") etc...making a big bag of 55 coins by adding to the K bag with its 10 coins.
The composite bag will weigh anything from 550 gms if the target is A, (551gms=target B, etc....) to 560 gms if the target is K.
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