Friday gold puzzle – can you crack it?

Here’s a bit of Friday gold bar fun via an interesting puzzle sitewe found…

You have nine small bars of gold, eight of which weigh 100 grams, the ninth gold bar weighs 110 grams.

The gold bars have got mixed up and being identical in appearance it is impossible to tell which is the 110 gram bar.

Fortunately you have a set of balance scales. But the scales can only be used twice, so using the scales to weigh two combinations of bars, how can you find the heavier bar of gold?

Go to next page for the solution.

Place three bars of gold in both scale pans, if they balance, remove those bars. Take the remaining three bars and place one in each of the two scale pans, if the the two bars balance, the remaining un-weighed bar is heaviest, if the bars do not balance, the heavier bar is the heaviest.

If the initial weighing did not balance, take the three bars from the heavier pan and place one in each of the two scale pans, if the the two bars balance, the remaining un-weighed bar is heaviest, if the bars do not balance, the heavier bar is the heaviest.

About the Author

Will Bancroft is one of the co-founders and COO of the Real Asset Co.