Brainteasers

[Oyvoyvoyv]

nordlead said:
ok, a new problem for those who read this thread

You have a pile of 24 coins. Twenty-three of these coins have the same weight, and one is heavier. Your task is to determine which coin is heavier and do so in the minimum number of weighings. You are given a beam balance (scale), which will compare the weight of any two sets of coins out of the total set of 24 coins. How many weighings are required to identify the heavier coin?

 

 Hmm. I'm saying 3.

First I'd break them into 3 piles. If it goes even, neither has the heavier coin. If it goes uneven, you know where it is. Either way, you know which 8 pile you have the heavier one in.

Secondly, you do the same with 3-3-2. Weigh 3-3, and have the same concept as in 1.

Third. If it was in the 2 group, simply weigh them against each other. If it was in the 3 one, weigh 2 against each other, if it balances, it's the last one.

 

Hey, mine was better than WoW's!_?