Out of 10 coins, one weighs less then the others. You have a balance scale. How can you determine which one weighs less in 3 weighs?
Divide these 10 coins into 3 stacks of 3 coins each with one coin remaining. Two weighs will estalish if any stack contains the less weighing coin as that stack will weigh less.
If all stacks weigh same then the remaining coin is least weight.
Else the less weighing stack contains the coin. Again take two coins from that stack and place each on two sides of scale. If they weigh same, remaining coin is least weight else, the one which weighs less.
you divide them in 2 staks 5 and 5 of each one
after one weigh you establish which wheigs less…there is the coin we are looking for
you take one coin out of this stack…
you divide the other 4 reamining coins in 2 stacks 2 coins each..
after a second wheigh if they whey the same then the coin you took out is the ONE…if not…
the stack wich wheigs less is the one with the coin….with other words there are only 2 coins to compair ….you do that after a third wheigh…
Obs:the third wheigh may not be necesarry
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We have 10 Coins. Divide it into two groups, A & B (eaching having 5-5 coins)
1st weighing:
Weigh A & B and see which one weighs less, for example lets say B weighs less. So take all 5 coins from B.
2nd weighing:
Now we have 5 coins from B. Take out any 1 coin and keep it aside. Divide the rest 4 into two groups B1 & B2.
If both weighs same, then the coin which we kept aside is the coin which weighs less.
Or lets say, if B1 weighs less, take the 2 coins from B1.
3rd Weighing:
We got 2 coins from B1, weigh it and we will get the coin which weighs less.
:D
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