There are an even balance and one weight of 2 kg and 9 kg each.
How many times as few as possible should I use even balance in order to take 50 kg gold dust out of a heap of gold dust in front of me ?
I can use gold dust that was already weighed and taken as a weight.
How many times as few as possible should I use even balance in order to take 50 kg gold dust out of a heap of gold dust in front of me ?
I can use gold dust that was already weighed and taken as a weight.
Answer
Then I can take 16 kg gold dust.
Then I can take 25 kg gold dust.
The total of the gold dust which I took out is three times in becoming 50 kg.
Three times
Solution
The first time :
I take 9 kg of balanced gold dust out of a heap of gold dust by 9 kg weight.
The second time:
I put both of 9 kg weight and 9 kg gold dust weighed on one side of even balance, and put both of 2kg weight and 16 kg gold dust on the other side.
Then I can take 16 kg gold dust.
The third time:
I put both of 9 kg weight and 16 kg gold dust weighed on one side of even balance, and put 25 kg gold dust on the other side.
Then I can take 25 kg gold dust.
The total of the gold dust which I took out is three times in becoming 50 kg.
