The heaviest of the little bags of gold
technical sheet
- Name : The heaviest of the little bags of gold
- Categories : Mathematical Riddles
- Comments : 0
We have 9 small bags of gold and a balance with 2 trays perfectly balanced. One of the small bags of gold is heavier than the others.
How can one identify with certainty what is this bag, in only 2 weighings?
Discover the solution of this riddle
To succeed in identifying the bag in only 2 weighings, it is necessary to make bundles of 3 small bags.
We take 2 packets at random and put 1 (of 3 small bags) on each tray. If the first weigh is balanced, the heaviest bag is in the remaining package, otherwise it is in the heavier package that is taken to make the 2nd weigh.
So we still have 3 bags among which hides the one we are looking for. We proceed in the same way, we take 2 small bags and put them on the scale. If it's balanced, the heaviest bag of gold is the one that has not been weighed, otherwise it's the one to designate the scale.