The "3 Weighings Only" method is based on the logic that if we have a set of coins, and we weigh them in groups of three, the counterfeit coin will either be lighter or heavier than the other coins. By comparing the weights of each group, we can determine which group contains the counterfeit coin.
No, this method can only be used for a set of 12 coins. If there are more than 12 coins, it will not work as we need to have 3 groups of 3 coins and one individual coin for the third weighing.
Yes, there are a few conditions that need to be met for this method to work. The coins should all have the same weight except for one counterfeit coin. Also, the scale used for weighing should be accurate and precise.
This method can identify the counterfeit coin in a set of 12 coins. However, if we have additional information about the counterfeit coin, such as whether it is heavier or lighter than the other coins, we can use this method to identify the counterfeit coin in a set of 13, 14, or 15 coins.
It depends on the number of coins and the available information. In some cases, this method may not be the most efficient, but it is a reliable and logical approach that can be used in many situations where a counterfeit coin needs to be identified.