What bag has the lighter coins?!
Question: There's eight bags full of coins; all eight bags have the same number of exactly similar coins, but the coins in one of the bags only weigh 1 gram each - half of what they weigh in the remaining seven bags. Using a weight scales only once (one reading) and being allowed to handle the bags and coins, how do you determine which bag contains the lighter coins?
PS - Please don't say pick up the coins and try to feel which ones are lighter, I said one gram but I could have said 0.00000000000000001 grams
Answers: There's eight bags full of coins; all eight bags have the same number of exactly similar coins, but the coins in one of the bags only weigh 1 gram each - half of what they weigh in the remaining seven bags. Using a weight scales only once (one reading) and being allowed to handle the bags and coins, how do you determine which bag contains the lighter coins?
PS - Please don't say pick up the coins and try to feel which ones are lighter, I said one gram but I could have said 0.00000000000000001 grams
You must first label the bags 1-8. Then take the number of coins out of the bag that is equal to the number on the bag. For instance, take 1 coin out of bag 1, two coins out of bag 2, etc. You should have a total of 36 coins. If all of the coins weighed the correct 2 grams, than the scale should read 72. But because 1 of the bags has coins that only weigh 1 gram, then the weight will be different. If the weight is 1 gram off, then it is bag number 1 because it had only 1 coin exhibited, if it is 2 grams off then it is bag number two, etc. I hope this helps you.
put all the bags on the scale
then remove them one by one until one bag is lighter (removes less)
What sort of scale? the one that has one side? or the one that has two?
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