There are 80 coins, among them one coin weighs less compared
to other. You are given a physical balance to weigh. In how
many wieghings the odd coin can be found.
Answer Posted / navya
First you take 30 coins and balance them with another 30. 20 coins are left "unweighd" If the weights are equal, you will have 20 coins left. Otherwise you will have a maximum of 30 coins left where the lighter coin is.
Take these 30 and weigh 10 coins against 10 (10 left over), and you will now have a maximum of 10 coins.
Take these 10, weigh 4 against 4 (2 left over), maximum 4 coins left.
Take these 4 coins, pair them up 2 and 2. Maximum 2 coins left.
Take these two coins and pair them up against eachother and you will find the lighter one
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